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

Pull vfs fixes from Al Viro:
 "A couple of fixes (-stable fodder) + dead code removal after the
  overlayfs fix.

  I agree that it's better to separate from the fix part to make
  backporting easier, but IMO it's not worth delaying said dead code
  removal until the next window"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  Don't reset ->total_link_count on nested calls of vfs_path_lookup()
  ovl: get rid of the dead code left from broken (and disabled) optimizations
  ovl: fix permission checking for setattr

Author: torvalds

fs/namei.c

@@ -1996,7 +1996,6 @@ static const char *path_init(struct nameidata *nd, unsigned flags)
 	nd->last_type = LAST_ROOT; /* if there are only slashes... */
 	nd->flags = flags | LOOKUP_JUMPED | LOOKUP_PARENT;
 	nd->depth = 0;
-	nd->total_link_count = 0;
 	if (flags & LOOKUP_ROOT) {
 		struct dentry *root = nd->root.dentry;
 		struct inode *inode = root->d_inode;

fs/overlayfs/copy_up.c

@@ -195,8 +195,7 @@ int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat)
 
 static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
 			      struct dentry *dentry, struct path *lowerpath,
-			      struct kstat *stat, struct iattr *attr,
-			      const char *link)
+			      struct kstat *stat, const char *link)
 {
 	struct inode *wdir = workdir->d_inode;
 	struct inode *udir = upperdir->d_inode;
@@ -240,8 +239,6 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
 
 	mutex_lock(&newdentry->d_inode->i_mutex);
 	err = ovl_set_attr(newdentry, stat);
-	if (!err && attr)
-		err = notify_change(newdentry, attr, NULL);
 	mutex_unlock(&newdentry->d_inode->i_mutex);
 	if (err)
 		goto out_cleanup;
@@ -286,8 +283,7 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
  * that point the file will have already been copied up anyway.
  */
 int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
-		    struct path *lowerpath, struct kstat *stat,
-		    struct iattr *attr)
+		    struct path *lowerpath, struct kstat *stat)
 {
 	struct dentry *workdir = ovl_workdir(dentry);
 	int err;
@@ -345,26 +341,19 @@ int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
 	}
 	upperdentry = ovl_dentry_upper(dentry);
 	if (upperdentry) {
-		unlock_rename(workdir, upperdir);
+		/* Raced with another copy-up?  Nothing to do, then... */
 		err = 0;
-		/* Raced with another copy-up?  Do the setattr here */
-		if (attr) {
-			mutex_lock(&upperdentry->d_inode->i_mutex);
-			err = notify_change(upperdentry, attr, NULL);
-			mutex_unlock(&upperdentry->d_inode->i_mutex);
-		}
-		goto out_put_cred;
+		goto out_unlock;
 	}
 
 	err = ovl_copy_up_locked(workdir, upperdir, dentry, lowerpath,
-				 stat, attr, link);
+				 stat, link);
 	if (!err) {
 		/* Restore timestamps on parent (best effort) */
 		ovl_set_timestamps(upperdir, &pstat);
 	}
 out_unlock:
 	unlock_rename(workdir, upperdir);
-out_put_cred:
 	revert_creds(old_cred);
 	put_cred(override_cred);
 
@@ -406,7 +395,7 @@ int ovl_copy_up(struct dentry *dentry)
 		ovl_path_lower(next, &lowerpath);
 		err = vfs_getattr(&lowerpath, &stat);
 		if (!err)
-			err = ovl_copy_up_one(parent, next, &lowerpath, &stat, NULL);
+			err = ovl_copy_up_one(parent, next, &lowerpath, &stat);
 
 		dput(parent);
 		dput(next);

fs/overlayfs/inode.c

@@ -12,8 +12,7 @@
 #include <linux/xattr.h>
 #include "overlayfs.h"
 
-static int ovl_copy_up_last(struct dentry *dentry, struct iattr *attr,
-			    bool no_data)
+static int ovl_copy_up_truncate(struct dentry *dentry)
 {
 	int err;
 	struct dentry *parent;
@@ -30,10 +29,8 @@ static int ovl_copy_up_last(struct dentry *dentry, struct iattr *attr,
 	if (err)
 		goto out_dput_parent;
 
-	if (no_data)
-		stat.size = 0;
-
-	err = ovl_copy_up_one(parent, dentry, &lowerpath, &stat, attr);
+	stat.size = 0;
+	err = ovl_copy_up_one(parent, dentry, &lowerpath, &stat);
 
 out_dput_parent:
 	dput(parent);
@@ -49,13 +46,13 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
 	if (err)
 		goto out;
 
-	upperdentry = ovl_dentry_upper(dentry);
-	if (upperdentry) {
+	err = ovl_copy_up(dentry);
+	if (!err) {
+		upperdentry = ovl_dentry_upper(dentry);
+
 		mutex_lock(&upperdentry->d_inode->i_mutex);
 		err = notify_change(upperdentry, attr, NULL);
 		mutex_unlock(&upperdentry->d_inode->i_mutex);
-	} else {
-		err = ovl_copy_up_last(dentry, attr, false);
 	}
 	ovl_drop_write(dentry);
 out:
@@ -353,7 +350,7 @@ struct inode *ovl_d_select_inode(struct dentry *dentry, unsigned file_flags)
 			return ERR_PTR(err);
 
 		if (file_flags & O_TRUNC)
-			err = ovl_copy_up_last(dentry, NULL, true);
+			err = ovl_copy_up_truncate(dentry);
 		else
 			err = ovl_copy_up(dentry);
 		ovl_drop_write(dentry);

fs/overlayfs/overlayfs.h

@@ -194,7 +194,6 @@ void ovl_cleanup(struct inode *dir, struct dentry *dentry);
 /* copy_up.c */
 int ovl_copy_up(struct dentry *dentry);
 int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
-		    struct path *lowerpath, struct kstat *stat,
-		    struct iattr *attr);
+		    struct path *lowerpath, struct kstat *stat);
 int ovl_copy_xattr(struct dentry *old, struct dentry *new);
 int ovl_set_attr(struct dentry *upper, struct kstat *stat);