[Qemu-devel] Sparse file support under windows

* [Qemu-devel] Sparse file support under windows
@ 2006-06-05  8:32 ZIGLIO, Frediano, VF-IT
  2006-06-14 14:00 ` Fabrice Bellard
  0 siblings, 1 reply; 5+ messages in thread
From: ZIGLIO, Frediano, VF-IT @ 2006-06-05  8:32 UTC (permalink / raw)
  To: qemu-devel

[-- Attachment #1: Type: text/plain, Size: 289 bytes --]

Hi,
  this patch add sparse file support under Windows (supported on NTFS).
It add a -s flag to qemu create and qemu convert. It contain also a new
implementation for ftruncate witch not fill manually space but only use
SetEndOfFile (so to handle correctly sparse file)

freddy77


[-- Attachment #2: sparse.diff --]
[-- Type: application/octet-stream, Size: 7681 bytes --]

diff -rub qemu-0.8.1.orig/block-qcow.c qemu-0.8.1/block-qcow.c

--- qemu-0.8.1.orig/block-qcow.c	Wed May  3 13:32:58 2006
+++ qemu-0.8.1/block-qcow.c	Wed May 31 15:39:59 2006
@@ -586,7 +586,7 @@
     l1_size = ((total_size * 512) + (1LL << shift) - 1) >> shift;
 
     header.l1_table_offset = cpu_to_be64(header_size);
-    if (flags) {
+    if (flags & BDRV_ENCRYPTED) {
         header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
     } else {
         header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
diff -rub qemu-0.8.1.orig/block.c qemu-0.8.1/block.c
--- qemu-0.8.1.orig/block.c	Wed May  3 13:32:58 2006
+++ qemu-0.8.1/block.c	Wed May 31 15:39:59 2006
@@ -753,18 +753,70 @@
     close(s->fd);
 }
 
+#ifdef _WIN32
+#include <windows.h>
+#include <winioctl.h>
+
+int qemu_ftruncate64(int fd, int64_t length)
+{
+    LARGE_INTEGER li;
+    LONG high;
+    HANDLE h;
+    BOOL res;
+
+    if ((GetVersion() & 0x80000000UL) && (length >> 32) != 0)
+	return -1;
+
+    h = (HANDLE)_get_osfhandle(fd);
+
+    /* get current position, ftruncate do not change position */
+    li.HighPart = 0;
+    li.LowPart = SetFilePointer (h, 0, &li.HighPart, FILE_CURRENT);
+    if (li.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
+	return -1;
+
+    high = length >> 32;
+    if (!SetFilePointer(h, (DWORD) length, &high, FILE_BEGIN))
+	return -1;
+    res = SetEndOfFile(h);
+
+    /* back to old position */
+    SetFilePointer(h, li.LowPart, &li.HighPart, FILE_BEGIN);
+    return res ? 0 : -1;
+}
+
+static int set_sparse(int fd)
+{
+    DWORD returned;
+    return (int) DeviceIoControl((HANDLE)_get_osfhandle(fd), FSCTL_SET_SPARSE,
+			     NULL, 0, NULL, 0, &returned, NULL);
+}
+#else
+#define set_sparse(fd) 1
+#endif
+
+
 static int raw_create(const char *filename, int64_t total_size,
                       const char *backing_file, int flags)
 {
     int fd;
 
-    if (flags || backing_file)
+    if ((flags & ~BDRV_FORCE_SPARSE) || backing_file)
         return -ENOTSUP;
 
     fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, 
               0644);
     if (fd < 0)
         return -EIO;
+
+    if (flags & BDRV_FORCE_SPARSE) {
+	if (!set_sparse(fd)) {
+	    close(fd);
+	    unlink(filename);
+	    return -EIO;
+	}
+    }
+
     ftruncate(fd, total_size * 512);
     close(fd);
     return 0;
diff -rub qemu-0.8.1.orig/qemu-img.c qemu-0.8.1/qemu-img.c
--- qemu-0.8.1.orig/qemu-img.c	Wed May  3 13:32:58 2006
+++ qemu-0.8.1/qemu-img.c	Wed May 31 15:39:59 2006
@@ -23,6 +23,10 @@
  */
 #include "vl.h"
 
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
 void *get_mmap_addr(unsigned long size)
 {
     return NULL;
@@ -132,9 +136,9 @@
            "QEMU disk image utility\n"
            "\n"
            "Command syntax:\n"
-           "  create [-e] [-b base_image] [-f fmt] filename [size]\n"
+           "  create [-e] [-s] [-b base_image] [-f fmt] filename [size]\n"
            "  commit [-f fmt] filename\n"
-           "  convert [-c] [-e] [-f fmt] filename [-O output_fmt] output_filename\n"
+           "  convert [-c] [-e] [-s] [-f fmt] filename [-O output_fmt] output_filename\n"
            "  info [-f fmt] filename\n"
            "\n"
            "Command parameters:\n"
@@ -148,6 +152,7 @@
            "  'output_fmt' is the destination format\n"
            "  '-c' indicates that target image must be compressed (qcow format only)\n"
            "  '-e' indicates that the target image must be encrypted (qcow format only)\n"
+	   "  '-s' enable sparse file where needed (currently Windows)\n"
            );
     printf("\nSupported format:");
     bdrv_iterate_format(format_print, NULL);
@@ -305,7 +310,7 @@
 
 static int img_create(int argc, char **argv)
 {
-    int c, ret, encrypted;
+    int c, ret, create_flags;
     const char *fmt = "raw";
     const char *filename;
     const char *base_filename = NULL;
@@ -313,9 +318,9 @@
     const char *p;
     BlockDriver *drv;
     
-    encrypted = 0;
+    create_flags = 0;
     for(;;) {
-        c = getopt(argc, argv, "b:f:he");
+        c = getopt(argc, argv, "b:f:hes");
         if (c == -1)
             break;
         switch(c) {
@@ -329,7 +334,10 @@
             fmt = optarg;
             break;
         case 'e':
-            encrypted = 1;
+	    create_flags |= BDRV_ENCRYPTED;
+            break;
+	case 's':
+	    create_flags |= BDRV_FORCE_SPARSE;
             break;
         }
     }
@@ -363,14 +371,14 @@
         error("Unknown file format '%s'", fmt);
     printf("Formating '%s', fmt=%s",
            filename, fmt);
-    if (encrypted)
+    if (create_flags & BDRV_ENCRYPTED)
         printf(", encrypted");
     if (base_filename) {
         printf(", backing_file=%s",
                base_filename);
     }
-    printf(", size=%lld kB\n", (long long) (size / 1024));
-    ret = bdrv_create(drv, filename, size / 512, base_filename, encrypted);
+    printf(", size=%" PRINTF_LL(d) " kB\n", (long long) (size / 1024));
+    ret = bdrv_create(drv, filename, size / 512, base_filename, create_flags);
     if (ret < 0) {
         if (ret == -ENOTSUP) {
             error("Formatting or formatting option not supported for file format '%s'", fmt);
@@ -475,7 +483,7 @@
 
 static int img_convert(int argc, char **argv)
 {
-    int c, ret, n, n1, compress, cluster_size, cluster_sectors, encrypt;
+    int c, ret, n, n1, compress, cluster_size, cluster_sectors, create_flags;
     const char *filename, *fmt, *out_fmt, *out_filename;
     BlockDriver *drv;
     BlockDriverState *bs, *out_bs;
@@ -486,9 +494,9 @@
     fmt = NULL;
     out_fmt = "raw";
     compress = 0;
-    encrypt = 0;
+    create_flags = 0;
     for(;;) {
-        c = getopt(argc, argv, "f:O:hce");
+        c = getopt(argc, argv, "f:O:hces");
         if (c == -1)
             break;
         switch(c) {
@@ -505,7 +513,10 @@
             compress = 1;
             break;
         case 'e':
-            encrypt = 1;
+            create_flags |= BDRV_ENCRYPTED;
+            break;
+        case 's':
+            create_flags |= BDRV_FORCE_SPARSE;
             break;
         }
     }
@@ -523,12 +534,12 @@
         error("Unknown file format '%s'", fmt);
     if (compress && drv != &bdrv_qcow)
         error("Compression not supported for this file format");
-    if (encrypt && drv != &bdrv_qcow)
+    if ((create_flags & BDRV_ENCRYPTED) && drv != &bdrv_qcow)
         error("Encryption not supported for this file format");
-    if (compress && encrypt)
+    if (compress && (create_flags & BDRV_ENCRYPTED))
         error("Compression and encryption not supported at the same time");
     bdrv_get_geometry(bs, &total_sectors);
-    ret = bdrv_create(drv, out_filename, total_sectors, NULL, encrypt);
+    ret = bdrv_create(drv, out_filename, total_sectors, NULL, create_flags);
     if (ret < 0) {
         if (ret == -ENOTSUP) {
             error("Formatting not supported for file format '%s'", fmt);
diff -rub qemu-0.8.1.orig/vl.h qemu-0.8.1/vl.h
--- qemu-0.8.1.orig/vl.h	Wed May  3 13:32:58 2006
+++ qemu-0.8.1/vl.h	Wed May 31 15:39:59 2006
@@ -49,8 +49,8 @@
 #ifdef _WIN32
 #define lseek _lseeki64
 #define ENOTSUP 4096
-/* XXX: find 64 bit version */
-#define ftruncate chsize
+extern int qemu_ftruncate64(int, int64_t);
+#define ftruncate qemu_ftruncate64
 
 static inline char *realpath(const char *path, char *resolved_path)
 {
@@ -503,6 +509,10 @@
 #define BIOS_ATA_TRANSLATION_AUTO 0
 #define BIOS_ATA_TRANSLATION_NONE 1
 #define BIOS_ATA_TRANSLATION_LBA  2
+
+/* creation flags */
+#define BDRV_ENCRYPTED 1
+#define BDRV_FORCE_SPARSE 2
 
 void bdrv_set_geometry_hint(BlockDriverState *bs, 
                             int cyls, int heads, int secs);

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