[PATCH 0/2] xfstests: add cifs.ko server-side copy helper

[PATCH 0/2] xfstests: add cifs.ko server-side copy helper

[David Disseldorp]

In preparation for adding cifs.ko support to xfstests, this patch series
extends the cloner binary to support SMB2 server-side copies via
CIFS_IOC_COPYCHUNK_FILE, in addition to the existing Btrfs COW clone
functionality.

This could be split into a separate binary if deemed necessary, but
given the code overlap, I though it suitable to share the same source.

Feedback appreciated.

--

David Disseldorp (2):
      src/cloner: check filesystem type
      src/cloner: add CIFS_IOC_COPYCHUNK_FILE support

 configure.ac |   1 +
 src/cloner.c | 123 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------
 2 files changed, 114 insertions(+), 10 deletions(-)

[PATCH 1/2] src/cloner: check filesystem type

[David Disseldorp]

Limit clone requests to Btrfs only for the moment.

Signed-off-by: David Disseldorp <ddiss@suse.de>
---
 src/cloner.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/src/cloner.c b/src/cloner.c
index ccc2354..6fb40fa 100644
--- a/src/cloner.c
+++ b/src/cloner.c
@@ -22,6 +22,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/ioctl.h>
+#include <sys/vfs.h>
 #include <stdint.h>
 #include <stdbool.h>
 #include <fcntl.h>
@@ -30,6 +31,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
+#include <linux/magic.h>
 #ifdef HAVE_BTRFS_IOCTL_H
 #include <btrfs/ioctl.h>
 #else
@@ -47,6 +49,10 @@ struct btrfs_ioctl_clone_range_args {
 				   struct btrfs_ioctl_clone_range_args)
 #endif
 
+#ifndef BTRFS_SUPER_MAGIC
+#define BTRFS_SUPER_MAGIC    0x9123683E
+#endif
+
 static void
 usage(char *name, const char *msg)
 {
@@ -89,6 +95,41 @@ clone_file_range(int src_fd, int dst_fd, uint64_t src_off, uint64_t dst_off,
 	return ret;
 }
 
+static int
+cloner_check_fs_support(int src_fd, int dest_fd, unsigned int *fs_type)
+{
+	int ret;
+	struct statfs sfs;
+
+	ret = fstatfs(src_fd, &sfs);
+	if (ret != 0) {
+		printf("failed to stat source FS\n");
+		return errno;
+	}
+
+	if (sfs.f_type != BTRFS_SUPER_MAGIC) {
+		printf("unsupported source FS 0x%x\n",
+		       (unsigned int)sfs.f_type);
+		return ENOTSUP;
+	}
+
+	*fs_type = (unsigned int)sfs.f_type;
+
+	ret = fstatfs(dest_fd, &sfs);
+	if (ret != 0) {
+		printf("failed to stat destination FS\n");
+		return errno;
+	}
+
+	if (sfs.f_type != *fs_type) {
+		printf("dest FS type 0x%x does not match source 0x%x\n",
+		       (unsigned int)sfs.f_type, *fs_type);
+		return ENOTSUP;
+	}
+
+	return 0;
+}
+
 int
 main(int argc, char **argv)
 {
@@ -102,6 +143,7 @@ main(int argc, char **argv)
 	int dst_fd;
 	int ret;
 	int opt;
+	unsigned int fs_type = 0;
 
 	while ((opt = getopt(argc, argv, "s:d:l:")) != -1) {
 		char *sval_end;
@@ -162,6 +204,11 @@ main(int argc, char **argv)
 		goto err_src_close;
 	}
 
+	ret = cloner_check_fs_support(src_fd, dst_fd, &fs_type);
+	if (ret != 0) {
+		goto err_dst_close;
+	}
+
 	if (full_file) {
 		ret = clone_file(src_fd, dst_fd);
 	} else {
-- 
1.8.4.5

[PATCH 2/2] src/cloner: add CIFS_IOC_COPYCHUNK_FILE support

[David Disseldorp]

cifs.ko supports server-side copy offloads via CIFS_IOC_COPYCHUNK_FILE.
In handling the ioctl, the request is split into a series of
SMB2 FSCTL_SRV_COPYCHUNK wire requests, which may be handled by the SMB
server as a local read/write, or COW clone as is the case for Samba with
vfs_btrfs.

Signed-off-by: David Disseldorp <ddiss@suse.de>
---
 configure.ac |  1 +
 src/cloner.c | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++---------
 2 files changed, 68 insertions(+), 11 deletions(-)

diff --git a/configure.ac b/configure.ac
index 53459d8..d038f95 100644
--- a/configure.ac
+++ b/configure.ac
@@ -31,6 +31,7 @@ AC_HEADER_STDC
 			sys/fs/xfs_itable.h	\
 			xfs/platform_defs.h	\
 			btrfs/ioctl.h		\
+			cifs/ioctl.h		\
     ])
 
 AC_CHECK_HEADERS([xfs/xfs_log_format.h],,,[#include <xfs/libxfs.h>])
diff --git a/src/cloner.c b/src/cloner.c
index 6fb40fa..18c44b9 100644
--- a/src/cloner.c
+++ b/src/cloner.c
@@ -1,6 +1,5 @@
 /*
- *  Tiny program to perform file (range) clones using raw Btrfs ioctls.
- *  It should only be needed until btrfs-progs has an xfs_io equivalent.
+ *  Tiny program to perform file (range) clones using raw Btrfs and CIFS ioctls.
  *
  *  Copyright (C) 2014 SUSE Linux Products GmbH. All Rights Reserved.
  *
@@ -49,9 +48,21 @@ struct btrfs_ioctl_clone_range_args {
 				   struct btrfs_ioctl_clone_range_args)
 #endif
 
+#ifdef HAVE_CIFS_IOCTL_H
+#include <cifs/ioctl.h>
+#else
+
+#define CIFS_IOCTL_MAGIC 0xCF
+#define CIFS_IOC_COPYCHUNK_FILE _IOW(CIFS_IOCTL_MAGIC, 3, int)
+
+#endif
+
 #ifndef BTRFS_SUPER_MAGIC
 #define BTRFS_SUPER_MAGIC    0x9123683E
 #endif
+#ifndef CIFS_MAGIC_NUMBER
+#define CIFS_MAGIC_NUMBER    0xFE534D42
+#endif
 
 static void
 usage(char *name, const char *msg)
@@ -59,17 +70,19 @@ usage(char *name, const char *msg)
 	printf("Fatal: %s\n"
 	       "Usage:\n"
 	       "%s [options] <src_file> <dest_file>\n"
-	       "\tA full file clone (reflink) is performed by default, "
-	       "unless any of the following are specified:\n"
+	       "\tA full file clone is performed by default, "
+	       "unless any of the following are specified (Btrfs only):\n"
 	       "\t-s <offset>:	source file offset (default = 0)\n"
 	       "\t-d <offset>:	destination file offset (default = 0)\n"
-	       "\t-l <length>:	length of clone (default = 0)\n",
+	       "\t-l <length>:	length of clone (default = 0)\n\n"
+	       "\tBoth Btrfs and CIFS are supported. On Btrfs, a COW clone "
+	       "is attempted. On CIFS, a server-side copy is requested.\n",
 	       msg, name);
 	_exit(1);
 }
 
 static int
-clone_file(int src_fd, int dst_fd)
+clone_file_btrfs(int src_fd, int dst_fd)
 {
 	int ret = ioctl(dst_fd, BTRFS_IOC_CLONE, src_fd);
 	if (ret != 0)
@@ -78,8 +91,33 @@ clone_file(int src_fd, int dst_fd)
 }
 
 static int
-clone_file_range(int src_fd, int dst_fd, uint64_t src_off, uint64_t dst_off,
-		 uint64_t len)
+clone_file_cifs(int src_fd, int dst_fd)
+{
+	int ret = ioctl(dst_fd, CIFS_IOC_COPYCHUNK_FILE, src_fd);
+	if (ret != 0)
+		ret = errno;
+	return ret;
+}
+
+static int
+clone_file(unsigned int fs_type, int src_fd, int dst_fd)
+{
+	switch (fs_type) {
+	case BTRFS_SUPER_MAGIC:
+		return clone_file_btrfs(src_fd, dst_fd);
+		break;
+	case CIFS_MAGIC_NUMBER:
+		return clone_file_cifs(src_fd, dst_fd);
+		break;
+	default:
+		return ENOTSUP;
+		break;
+	}
+}
+
+static int
+clone_file_range_btrfs(int src_fd, int dst_fd, uint64_t src_off,
+		       uint64_t dst_off, uint64_t len)
 {
 	struct btrfs_ioctl_clone_range_args cr_args;
 	int ret;
@@ -96,6 +134,22 @@ clone_file_range(int src_fd, int dst_fd, uint64_t src_off, uint64_t dst_off,
 }
 
 static int
+clone_file_range(unsigned int fs_type, int src_fd, int dst_fd, uint64_t src_off,
+		 uint64_t dst_off, uint64_t len)
+{
+	switch (fs_type) {
+	case BTRFS_SUPER_MAGIC:
+		return clone_file_range_btrfs(src_fd, dst_fd, src_off, dst_off,
+					      len);
+		break;
+	case CIFS_MAGIC_NUMBER:	/* only supports full file server-side copies */
+	default:
+		return ENOTSUP;
+		break;
+	}
+}
+
+static int
 cloner_check_fs_support(int src_fd, int dest_fd, unsigned int *fs_type)
 {
 	int ret;
@@ -107,7 +161,8 @@ cloner_check_fs_support(int src_fd, int dest_fd, unsigned int *fs_type)
 		return errno;
 	}
 
-	if (sfs.f_type != BTRFS_SUPER_MAGIC) {
+	if ((sfs.f_type != BTRFS_SUPER_MAGIC)
+	 && (sfs.f_type != CIFS_MAGIC_NUMBER)) {
 		printf("unsupported source FS 0x%x\n",
 		       (unsigned int)sfs.f_type);
 		return ENOTSUP;
@@ -210,9 +265,10 @@ main(int argc, char **argv)
 	}
 
 	if (full_file) {
-		ret = clone_file(src_fd, dst_fd);
+		ret = clone_file(fs_type, src_fd, dst_fd);
 	} else {
-		ret = clone_file_range(src_fd, dst_fd, src_off, dst_off, len);
+		ret = clone_file_range(fs_type, src_fd, dst_fd, src_off,
+				       dst_off, len);
 	}
 	if (ret != 0) {
 		printf("clone failed: %s\n", strerror(ret));
-- 
1.8.4.5