Merge tag 'driver-core-4.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are three small fixes for 4.8-rc5.

  One for sysfs, one for kernfs, and one documentation fix, all for
  reported issues.  All of these have been in linux-next for a while"

* tag 'driver-core-4.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  sysfs: correctly handle read offset on PREALLOC attrs
  documentation: drivers/core/of: fix name of of_node symlink
  kernfs: don't depend on d_find_any_alias() when generating notifications

2 files changed, 28 insertions, 8 deletions

diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index e1574008adc9..2bcb86e6e6ca 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -840,21 +840,35 @@ repeat:
         mutex_lock(&kernfs_mutex);
 
         list_for_each_entry(info, &kernfs_root(kn)->supers, node) {
+                struct kernfs_node *parent;
                 struct inode *inode;
-                struct dentry *dentry;
 
+                /*
+                 * We want fsnotify_modify() on @kn but as the
+                 * modifications aren't originating from userland don't
+                 * have the matching @file available.  Look up the inodes
+                 * and generate the events manually.
+                 */
                 inode = ilookup(info->sb, kn->ino);
                 if (!inode)
                         continue;
 
-                dentry = d_find_any_alias(inode);
-                if (dentry) {
-                        fsnotify_parent(NULL, dentry, FS_MODIFY);
-                        fsnotify(inode, FS_MODIFY, inode, FSNOTIFY_EVENT_INODE,
-                                 NULL, 0);
-                        dput(dentry);
+                parent = kernfs_get_parent(kn);
+                if (parent) {
+                        struct inode *p_inode;
+
+                        p_inode = ilookup(info->sb, parent->ino);
+                        if (p_inode) {
+                                fsnotify(p_inode, FS_MODIFY | FS_EVENT_ON_CHILD,
+                                         inode, FSNOTIFY_EVENT_INODE, kn->name, 0);
+                                iput(p_inode);
+                        }
+
+                        kernfs_put(parent);
                 }
 
+                fsnotify(inode, FS_MODIFY, inode, FSNOTIFY_EVENT_INODE,
+                         kn->name, 0);
                 iput(inode);
         }
 
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index f35523d4fa3a..b803213d1307 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -114,9 +114,15 @@ static ssize_t sysfs_kf_read(struct kernfs_open_file *of, char *buf,
          * If buf != of->prealloc_buf, we don't know how
          * large it is, so cannot safely pass it to ->show
          */
-        if (pos || WARN_ON_ONCE(buf != of->prealloc_buf))
+        if (WARN_ON_ONCE(buf != of->prealloc_buf))
                 return 0;
         len = ops->show(kobj, of->kn->priv, buf);
+        if (pos) {
+                if (len <= pos)
+                        return 0;
+                len -= pos;
+                memmove(buf, buf + pos, len);
+        }
         return min(count, len);
 }