Merge branch 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block

* 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block:
  [PATCH] Remove SUID when splicing into an inode
  [PATCH] Add lockless helpers for remove_suid()
  [PATCH] Introduce generic_file_splice_write_nolock()
  [PATCH] Take i_mutex in splice_from_pipe()

1 files changed, 22 insertions, 8 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index 8558732e85c..cb26e33fd0f 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1884,11 +1884,10 @@ repeat:
  *      if suid or (sgid and xgrp)
  *              remove privs
  */
-int remove_suid(struct dentry *dentry)
+int should_remove_suid(struct dentry *dentry)
 {
         mode_t mode = dentry->d_inode->i_mode;
         int kill = 0;
-        int result = 0;
 
         /* suid always must be killed */
         if (unlikely(mode & S_ISUID))
@@ -1901,13 +1900,28 @@ int remove_suid(struct dentry *dentry)
         if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
                 kill |= ATTR_KILL_SGID;
 
-        if (unlikely(kill && !capable(CAP_FSETID))) {
-                struct iattr newattrs;
+        if (unlikely(kill && !capable(CAP_FSETID)))
+                return kill;
 
-                newattrs.ia_valid = ATTR_FORCE | kill;
-                result = notify_change(dentry, &newattrs);
-        }
-        return result;
+        return 0;
+}
+
+int __remove_suid(struct dentry *dentry, int kill)
+{
+        struct iattr newattrs;
+
+        newattrs.ia_valid = ATTR_FORCE | kill;
+        return notify_change(dentry, &newattrs);
+}
+
+int remove_suid(struct dentry *dentry)
+{
+        int kill = should_remove_suid(dentry);
+
+        if (unlikely(kill))
+                return __remove_suid(dentry, kill);
+
+        return 0;
 }
 EXPORT_SYMBOL(remove_suid);