[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Btrfs clone support in copy operations
From: |
Kieran Colford |
Subject: |
Btrfs clone support in copy operations |
Date: |
Tue, 05 Jul 2016 15:06:42 -0400 |
I've put together a patch for supporting the btrfs clone operation for
copying
diff --git a/src/fileio.c b/src/fileio.c
index b1f9d3c..d7c1e6e 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -21,6 +21,7 @@ along with GNU Emacs. If not, see
<http://www.gnu.org/licenses/>. */
#include <limits.h>
#include <fcntl.h>
#include "sysstdio.h"
+#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
@@ -1988,6 +1989,16 @@ permissions. */)
oldsize = out_st.st_size;
}
+ /* Perform the O(1) btrfs clone operation, if possible. */
+#ifdef __linux__
+# undef BTRFS_IOCTL_MAGIC
+# define BTRFS_IOCTL_MAGIC 0x94
+# undef BTRFS_IOC_CLONE
+# define BTRFS_IOC_CLONE _IOW (BTRFS_IOCTL_MAGIC, 9, int)
+ if (ioctl (ofd, BTRFS_IOC_CLONE, ifd) == 0)
+ goto done_copy;
+#endif
+
immediate_quit = 1;
QUIT;
while (true)
@@ -2011,6 +2022,8 @@ permissions. */)
immediate_quit = 0;
+ done_copy:
+
#ifndef MSDOS
/* Preserve the original file permissions, and if requested, also its
owner and group. */
--
Kieran Colford <address@hidden>
signature.asc
Description: This is a digitally signed message part
- Btrfs clone support in copy operations,
Kieran Colford <=