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Diffstat (limited to 'Documentation/filesystems/porting.rst')
| -rw-r--r-- | Documentation/filesystems/porting.rst | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst index 9100969e7de6..33cd56e2ca1a 100644 --- a/Documentation/filesystems/porting.rst +++ b/Documentation/filesystems/porting.rst @@ -1079,3 +1079,12 @@ On same-directory ->rename() the (tautological) update of .. is not protected by any locks; just don't do it if the old parent is the same as the new one. We really can't lock two subdirectories in same-directory rename - not without deadlocks. + +--- + +**mandatory** + +lock_rename() and lock_rename_child() may fail in cross-directory case, if +their arguments do not have a common ancestor. In that case ERR_PTR(-EXDEV) +is returned, with no locks taken. In-tree users updated; out-of-tree ones +would need to do so. |