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

4 files changed, 15 insertions, 31 deletions

diff --git a/fs/namei.c b/fs/namei.c
index d84d7c7515fc..0c3974cd3ecd 100644
--- a/fs/namei.c
+++ b/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;
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 871fcb67be97..0a8983492d91 100644
--- a/fs/overlayfs/copy_up.c
+++ b/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 @@ out_cleanup:
  * 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);
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index ec0c2a050043..4060ffde8722 100644
--- a/fs/overlayfs/inode.c
+++ b/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);
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index ea5a40b06e3a..e17154aeaae4 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/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);