Add support for file cloning in append/reget modes on Linux and FreeBSD

Signed-off-by: Phil Krylov <phil@krylov.eu>

Author: tuffnatty

configure.ac

@@ -380,10 +380,25 @@ case $host_os in
     AC_DEFINE([PTY_ZEROREAD], [1], [read(1) can return 0 for a non-closed fd])
 esac
 
-dnl Check linux/fs.h for FICLONE to support BTRFS's file clone operation
+dnl Check linux/fs.h for FICLONERANGE to support file clone operation
 case $host_os in
 linux*)
     AC_CHECK_HEADERS([linux/fs.h])
+    AC_MSG_CHECKING([for FICLONERANGE])
+    AC_EGREP_CPP([FICLONERANGE_IS_DEFINED],
+        [
+            #include <linux/fs.h>
+            #ifdef FICLONERANGE
+            FICLONERANGE_IS_DEFINED
+            #endif
+        ],
+        [
+            AC_DEFINE(HAVE_FICLONERANGE, 1, [Define if FICLONERANGE is supported on Linux])
+            AC_MSG_RESULT(yes)
+        ],
+        [
+            AC_MSG_RESULT(no)
+        ])
 esac
 
 dnl Check for copy_file_range(2) support (FreeBSD 13+)

lib/vfs/vfs.c

@@ -46,18 +46,14 @@
 #include <errno.h>
 #include <stdlib.h>
 
-#ifdef __linux__
-#ifdef HAVE_LINUX_FS_H
-#include <linux/fs.h>
-#endif
-#ifdef HAVE_SYS_IOCTL_H
-#include <sys/ioctl.h>
-#endif
-#elif defined(__FreeBSD__) && defined(HAVE_COPY_FILE_RANGE)
+#ifdef HAVE_FICLONERANGE
+#include <linux/fs.h>   // FICLONERANGE
+#include <sys/ioctl.h>  // ioctl()
+#elif defined(HAVE_COPY_FILE_RANGE)
 #include <unistd.h>  // COPY_FILE_RANGE_CLONE
-#elif defined(__APPLE__) && defined(HAVE_SYS_CLONEFILE_H)
+#elif defined(HAVE_SYS_CLONEFILE_H)
 #include <sys/clonefile.h>  // CLONE_NOOWNERCOPY
-#elif defined(__sun) && defined(HAVE_REFLINK)
+#elif defined(HAVE_REFLINK)
 #include <unistd.h>  // reflink()
 #endif
 
@@ -726,11 +722,12 @@ vfs_preallocate (int dest_vfs_fd, off_t src_fsize, off_t dest_fsize)
 int
 vfs_clone_file (int dest_vfs_fd, int src_vfs_fd)
 {
-#if defined(FICLONE) || defined(COPY_FILE_RANGE_CLONE)
+#if defined(FICLONERANGE) || defined(COPY_FILE_RANGE_CLONE)
     void *dest_fd = NULL;
     void *src_fd = NULL;
     struct vfs_class *dest_class;
     struct vfs_class *src_class;
+    off_t in_offset, out_offset;
 
     dest_class = vfs_class_find_by_handle (dest_vfs_fd, &dest_fd);
     if ((dest_class->flags & VFSF_LOCAL) == 0)
@@ -756,12 +753,26 @@ vfs_clone_file (int dest_vfs_fd, int src_vfs_fd)
         return (-1);
     }
 
-#if defined(FICLONE)
-    return ioctl (*(int *) dest_fd, FICLONE, *(int *) src_fd);
+    in_offset = mc_lseek (src_vfs_fd, 0, SEEK_CUR);
+    if (in_offset < 0)
+        return (-1);
+    out_offset = mc_lseek (dest_vfs_fd, 0, SEEK_CUR);
+    if (out_offset < 0)
+        return (-1);
+
+#if defined(FICLONERANGE)
+    {
+        struct file_clone_range fcr = { .src_fd = *(int *) src_fd,
+                                        .src_offset = in_offset,
+                                        .src_length = 0,
+                                        .dest_offset = out_offset };
+
+        return ioctl (*(int *) dest_fd, FICLONERANGE, &fcr);
+    }
 #elif defined(COPY_FILE_RANGE_CLONE)
     {
-        off_t in_offset = 0, out_offset = 0;
         ssize_t result;
+
         do
         {
             result = copy_file_range (*(int *) src_fd, &in_offset, *(int *) dest_fd, &out_offset,

src/filemanager/boxes.c

@@ -38,9 +38,6 @@
 #include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#ifdef HAVE_SYS_IOCTL_H
-#include <sys/ioctl.h>  // FICLONE
-#endif
 
 #include "lib/global.h"
 
@@ -634,7 +631,8 @@ configure_box (void)
         quick_widgets[6].state = WST_DISABLED;
 #endif
 
-#if !defined(FICLONE) && !defined(HAVE_COPY_FILE_RANGE) && !defined(HAVE_SYS_CLONEFILE_H) && !defined(HAVE_REFLINK)
+#if !defined(HAVE_FICLONERANGE) && !defined(HAVE_COPY_FILE_RANGE)                                  \
+    && !defined(HAVE_SYS_CLONEFILE_H) && !defined(HAVE_REFLINK)
         mc_global.vfs.file_cloning = FALSE;
         quick_widgets[7].state = WST_DISABLED;
 #endif

src/filemanager/file.c

@@ -59,9 +59,6 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
-#ifdef HAVE_SYS_IOCTL_H
-#include <sys/ioctl.h>  // FICLONE
-#endif
 
 #include "lib/global.h"
 #include "lib/tty/tty.h"
@@ -2593,7 +2590,7 @@ copy_file_file (file_op_context_t *ctx, const char *src_path, const char *dst_pa
     src_gid = src_stat.st_gid;
     file_size = src_stat.st_size;
 
-#if defined(__APPLE__) || defined(__sun)
+#if defined(HAVE_SYS_CLONEFILE_H) || defined(HAVE_REFLINK)
     // On macOS 10.12+ and Solaris 11.4+, the syscalls for file cloning respond for creation of the
     // destination file, so try them before mc_open to avoid handling various races later.
     // Full file cloning is not supported in append and reget modes.
@@ -2620,10 +2617,20 @@ copy_file_file (file_op_context_t *ctx, const char *src_path, const char *dst_pa
     if (!dst_exists)
         open_flags |= O_CREAT | O_EXCL;
     else if (ctx->do_append)
+#if defined(HAVE_FICLONERANGE) || defined(HAVE_COPY_FILE_RANGE)
+        // FICLONERANGE on Linux and copy_file_range(2) on FreeBSD support block-aligned ranges for
+        // cloning, but for not in O_APPEND mode. Use O_WRONLY + mc_lseek instead as we don't care
+        // about atomicity in our use cases.
+        open_flags |= mc_global.vfs.file_cloning ? O_WRONLY : O_APPEND;
+#else
         open_flags |= O_APPEND;
+#endif
     else
         open_flags |= O_CREAT | O_TRUNC;
 
+#if defined(HAVE_FICLONERANGE) || defined(HAVE_COPY_FILE_RANGE)
+open_dest:
+#endif
     while ((dest_desc = mc_open (dst_vpath, open_flags, src_mode)) < 0)
     {
         if (errno != EEXIST)
@@ -2650,13 +2657,26 @@ copy_file_file (file_op_context_t *ctx, const char *src_path, const char *dst_pa
     appending = ctx->do_append;
     ctx->do_append = FALSE;
 
-#if defined(FICLONE) || defined(HAVE_COPY_FILE_RANGE)
-    // Try clone the file first. It's not supported in append mode
-    if (mc_global.vfs.file_cloning && !appending && vfs_clone_file (dest_desc, src_desc) == 0)
+#if defined(HAVE_FICLONERANGE) || defined(HAVE_COPY_FILE_RANGE)
+    // Try clone the file first, but not if the file is in O_APPEND mode
+    if (mc_global.vfs.file_cloning && !(open_flags & O_APPEND))
     {
-        dst_status = DEST_FULL;
-        return_status = FILE_CONT;
-        goto ret;
+        if ((appending ? mc_lseek (dest_desc, 0, SEEK_END) >= 0 : TRUE)
+            && vfs_clone_file (dest_desc, src_desc) == 0)
+        {
+            dst_status = DEST_FULL;
+            return_status = FILE_CONT;
+            goto ret;
+        }
+        else if (appending && !(open_flags & O_APPEND))
+        {
+            // Cloning append has failed, resort to normal append
+            ctx->do_append = TRUE;
+            mc_close (dest_desc);
+            dst_status = DEST_NONE;
+            open_flags = (open_flags & ~O_WRONLY) | O_APPEND;
+            goto open_dest;
+        }
     }
 #endif
 

tests/lib/vfs/vfs_clone_file.c

@@ -30,14 +30,14 @@
 #include <stdarg.h>
 #include <stdlib.h>
 
-#ifdef __linux__
-#include <linux/fs.h>   // FICLONE
+#ifdef HAVE_FICLONERANGE
+#include <linux/fs.h>   // FICLONERANGE
 #include <sys/ioctl.h>  // ioctl()
-#elif defined(__FreeBSD__) && defined(HAVE_COPY_FILE_RANGE)
+#elif defined(HAVE_COPY_FILE_RANGE)
 #include <unistd.h>  // copy_file_range()
-#elif defined(__sun) && defined(HAVE_REFLINK)
+#elif defined(HAVE_REFLINK)
 #include <unistd.h>  // reflink()
-#elif defined(__APPLE__) && defined(HAVE_SYS_CLONEFILE_H)
+#elif defined(HAVE_SYS_CLONEFILE_H)
 #include <sys/clonefile.h>  // clonefile()
 #endif
 
@@ -53,7 +53,7 @@ static gboolean clone_syscall__call_arguments_are_proper = FALSE;
 static const char test_filename1[] = "mctestclone1.tst";
 static const char test_filename2[] = "mctestclone2.tst";
 
-#ifdef __FreeBSD__
+#ifdef HAVE_COPY_FILE_RANGE
 /* @Mock */
 ssize_t
 copy_file_range (int infd, off_t *inoffp, int outfd, off_t *outoffp, size_t len, unsigned int flags)
@@ -71,7 +71,7 @@ copy_file_range (int infd, off_t *inoffp, int outfd, off_t *outoffp, size_t len,
 }
 #endif
 
-#ifdef __linux__
+#ifdef HAVE_FICLONERANGE
 #ifdef __GLIBC__
 /* @Mock */
 int
@@ -85,12 +85,12 @@ ioctl (int fd, int request, ...)
     (void) fd;
 
     clone_syscall__call_count++;
-    clone_syscall__call_arguments_are_proper = (request == FICLONE);
+    clone_syscall__call_arguments_are_proper = (request == FICLONERANGE);
     return -1;
 }
 #endif
 
-#if defined(HAVE_SYS_CLONEFILE_H)
+#ifdef HAVE_SYS_CLONEFILE_H
 /* @Mock */
 int
 my_clonefile (const char *src, const char *dst, uint32_t flags)
@@ -104,7 +104,7 @@ my_clonefile (const char *src, const char *dst, uint32_t flags)
 }
 #endif
 
-#if defined(HAVE_REFLINK)
+#ifdef HAVE_REFLINK
 /* @Mock */
 int
 reflink (const char *src, const char *dst, int preserve)
@@ -182,7 +182,7 @@ START_TEST (test_vfs_clone_file)
     vfs_clone_file (fdout, fdin);
 
     // then
-#if defined(FICLONE) || defined(HAVE_COPY_FILE_RANGE)
+#if defined(HAVE_FICLONERANGE) || defined(HAVE_COPY_FILE_RANGE)
     ck_assert (clone_syscall__call_count > 0);
     ck_assert (clone_syscall__call_arguments_are_proper);
 #else