libfuse: Notifying the kernel of deletion.

libfuse part to allow a FUSE file-system to tell the kernel when a
file or directory is deleted. If the specified dentry has the
specified inode number, the kernel will unhash it.

Signed-off-by: John Muir <john@jmuir.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

2 files changed, 25 insertions, 0 deletions

diff --git a/include/fuse_kernel.h b/include/fuse_kernel.h
index 039eb1f..89e941a 100644
--- a/include/fuse_kernel.h
+++ b/include/fuse_kernel.h
@@ -79,6 +79,7 @@
  *
  * 7.18
  *  - add FUSE_IOCTL_DIR flag
+ *  - add FUSE_NOTIFY_DELETE
  *  - add FUSE_MMAP and FUSE_MUNMAP
  */
 
@@ -322,6 +323,7 @@ enum fuse_notify_code {
 	FUSE_NOTIFY_INVAL_ENTRY = 3,
 	FUSE_NOTIFY_STORE = 4,
 	FUSE_NOTIFY_RETRIEVE = 5,
+	FUSE_NOTIFY_DELETE = 6,
 	FUSE_NOTIFY_CODE_MAX,
 };
 
@@ -667,6 +669,13 @@ struct fuse_notify_inval_entry_out {
 	__u32	padding;
 };
 
+struct fuse_notify_delete_out {
+	__u64	parent;
+	__u64	child;
+	__u32	namelen;
+	__u32	padding;
+};
+
 struct fuse_notify_store_out {
 	__u64	nodeid;
 	__u64	offset;
diff --git a/include/fuse_lowlevel.h b/include/fuse_lowlevel.h
index 6435937..8ed555e 100644
--- a/include/fuse_lowlevel.h
+++ b/include/fuse_lowlevel.h
@@ -1323,6 +1323,22 @@ int fuse_lowlevel_notify_inval_entry(struct fuse_chan *ch, fuse_ino_t parent,
                                      const char *name, size_t namelen);
 
 /**
+ * Notify to invalidate parent attributes and delete the dentry matching
+ * parent/name if the dentry's inode number matches child (otherwise it
+ * will invalidate the matching dentry).
+ *
+ * @param ch the channel through which to send the notification
+ * @param parent inode number
+ * @param child inode number
+ * @param name file name
+ * @param namelen strlen() of file name
+ * @return zero for success, -errno for failure
+ */
+int fuse_lowlevel_notify_delete(struct fuse_chan *ch,
+				fuse_ino_t parent, fuse_ino_t child,
+				const char *name, size_t namelen);
+
+/**
  * Store data to the kernel buffers
  *
  * Synchronously store data in the kernel buffers belonging to the