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[Qemu-devel] [PATCH V4 2/5] block: Add WIN32 platform support for backin
From: |
Xu Wang |
Subject: |
[Qemu-devel] [PATCH V4 2/5] block: Add WIN32 platform support for backing_file_loop_check() |
Date: |
Mon, 22 Jul 2013 04:05:46 -0400 |
Method of get_inode is different between Linux and WIN32 plateform.
This patch added inode caculate method on Windows plateform so that
backing file check could work on Windows plateform.
Signed-off-by: Xu Wang <address@hidden>
---
block.c | 160 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 152 insertions(+), 8 deletions(-)
diff --git a/block.c b/block.c
index aea653d..3e23b67 100644
--- a/block.c
+++ b/block.c
@@ -51,6 +51,10 @@
#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress
*/
+#ifdef _WIN32
+#define MAX_PATH_LEN 8192
+#endif
+
typedef enum {
BDRV_REQ_COPY_ON_READ = 0x1,
BDRV_REQ_ZERO_WRITE = 0x2,
@@ -4433,6 +4437,147 @@ bdrv_acct_done(BlockDriverState *bs, BlockAcctCookie
*cookie)
bs->total_time_ns[cookie->type] += get_clock() - cookie->start_time_ns;
}
+#ifdef _WIN32
+static int get_lnk_target_file(const char *lnk_file, char *filepath)
+{
+ unsigned int flag, offset;
+ unsigned int sflag;
+ char uch;
+ int i = 0;
+
+ FILE *fd = fopen(lnk_file, "rb");
+ if (!fd) {
+ error_report("Open file %s failed.", lnk_file);
+ return -1;
+ }
+
+ /* Check if the file is shortcuts by reading first 4 bytes if it's 0x4c */
+ if (fread(&flag, 4, 1, fd) != 1) {
+ error_report("Read 0x4c field of %s failed.", lnk_file);
+ goto err;
+ }
+
+ if (flag != 0x4c) {
+ error_report("%s is not a lnk file.", lnk_file);
+ goto err;
+ }
+
+ /* Parse flags on offset 0x14 */
+ if (fseek(fd, 0x14, SEEK_SET)) {
+ error_report("Seek flags of %s failed.", lnk_file);
+ goto err;
+ }
+
+ if (fread(&flag, 4, 1, fd) != 1) {
+ error_report("Read flags of %s failed.", lnk_file);
+ goto err;
+ }
+
+ /* seek to the length of item ID list */
+ if (fseek(fd, 0x4c, SEEK_SET)) {
+ error_report("Seek %s length of item ID list failed.", lnk_file);
+ goto err;
+ }
+
+ /* Parse Shell item ID list */
+ if (flag & 0x01) {
+ /* Get the length of SHITEMID */
+ if (fread(&sflag, 2, 1, fd) != 1) {
+ error_report("Read %s length of SHITEMID failed.", lnk_file);
+ goto err;
+ }
+
+ /* Skip SHITEMID */
+ if (fseek(fd, sflag, SEEK_CUR)) {
+ error_report("Skip SHITEMID of %s failed.", lnk_file);
+ goto err;
+ }
+ }
+
+ offset = ftell(fd);
+ if (offset == -1) {
+ error_report("ftell() of %s failed.", lnk_file);
+ goto err;
+ }
+ /* Read offset of local path */
+ if (fseek(fd, offset + 0x10, SEEK_SET)) {
+ error_report("Seek offset of %s failed.", lnk_file);
+ goto err;
+ }
+ if (fread(&flag, 4, 1, fd) != 1) {
+ error_report("Read offset of %s failed.", lnk_file);
+ goto err;
+ }
+ /* Seek to the start of target file path */
+ if (fseek(fd, flag + offset, SEEK_SET)) {
+ error_report("Seek target file path of %s failed.", lnk_file);
+ goto err;
+ }
+
+ do {
+ if (fread(&uch, 1, 1, fd) != 1) {
+ error_report("Read target path of %s failed.", lnk_file);
+ goto err;
+ }
+ filepath[i++] = uch;
+ } while ((i <= MAX_PATH_LEN) && (uch != '\0'));
+
+ fclose(fd);
+ return 0;
+
+err:
+ fclose(fd);
+ return -1;
+}
+#endif
+
+static long get_inode(const char *filename)
+{
+ #ifdef _WIN32
+ char pbuf[MAX_PATH_LEN], *p;
+ long inode;
+ struct stat sbuf;
+ char path[MAX_PATH_LEN];
+ int len;
+
+ /* If filename contains .lnk, it's a shortcuts. Target file
+ * need to be parsed.
+ */
+ len = strlen(filename);
+ if ((len > 4) && (strcmp(filename + len - 4, ".lnk"))) {
+ if (get_lnk_target_file(filename, path)) {
+ error_report("Parse .lnk file %s failed.", filename);
+ return -1;
+ }
+ } else {
+ memcpy(path, filename, sizeof(filename));
+ }
+
+ if (stat(path, &sbuf) == -1) {
+ error_report("get file %s stat error.", path);
+ return -1;
+ }
+ if (GetFullPathName(path, MAX_PATH_LEN, pbuf, &p) != 0) {
+ inode = 11003;
+ for (p = pbuf; *p != '\0'; p++) {
+ inode = inode * 31 + *(unsigned char *)p;
+ }
+ return (inode * 911) & 0x7FFF;
+ }
+
+ return -1;
+ #else
+ struct stat sbuf;
+
+ if (stat(filename, &sbuf) == -1) {
+ error_report("get file %s stat error.", filename);
+ return -1;
+ }
+
+ return sbuf.st_ino;
+ #endif
+}
+
static gboolean str_equal_func(gconstpointer a, gconstpointer b)
{
return strcmp(a, b) == 0;
@@ -4456,7 +4601,6 @@ bool bdrv_backing_file_loop_check(const char *filename,
const char *fmt,
GHashTable *inodes;
BlockDriverState *bs;
BlockDriver *drv;
- struct stat sbuf;
long inode = 0;
int ret;
char fbuf[1024];
@@ -4468,11 +4612,11 @@ bool bdrv_backing_file_loop_check(const char *filename,
const char *fmt,
if (access(filename, F_OK)) {
inode = -1;
} else {
- if (stat(filename, &sbuf) == -1) {
- error_report("Get file %s stat failed.", filename);
+ inode = get_inode(filename);
+ if (inode == -1) {
+ error_report("Get file %s inode failed.", filename);
goto err;
}
- inode = (long)sbuf.st_ino;
}
filename = backing_file;
@@ -4481,11 +4625,11 @@ bool bdrv_backing_file_loop_check(const char *filename,
const char *fmt,
}
while (filename && (filename[0] != '\0')) {
- if (stat(filename, &sbuf) == -1) {
- error_report("Get file %s stat failed.", filename);
- goto err;
+ inode = get_inode(filename);
+ if (inode == -1) {
+ error_report("Get file %s inode failed.", filename);
+ goto err;
}
- inode = (long)sbuf.st_ino;
if (g_hash_table_lookup_extended(inodes, &inode, NULL, NULL)) {
error_report("Backing file '%s' creates an infinite loop.",
--
1.8.1.4