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storage: Break out actual raw cloning to separate function.

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The CreateRaw function has some 'file' only assumptions, so break the agnostic
cloning bits to a separate function.
This commit is contained in:
Cole Robinson 2009-06-25 18:34:59 -04:00
parent 16e4833492
commit a256fccfe1
1 changed files with 92 additions and 68 deletions
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160
src/storage_backend.c
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@ -103,6 +103,95 @@ enum {
TOOL_QCOW_CREATE,
};
static int
virStorageBackendCopyToFD(virConnectPtr conn,
virStorageVolDefPtr vol,
virStorageVolDefPtr inputvol,
int fd,
unsigned long long *total)
{
int inputfd = -1;
int amtread = -1;
int ret = -1;
unsigned long long remain;
size_t bytes = 1024 * 1024;
char zerobuf[512];
char *buf = NULL;
if (inputvol) {
if ((inputfd = open(inputvol->target.path, O_RDONLY)) < 0) {
virReportSystemError(conn, errno,
_("could not open input path '%s'"),
inputvol->target.path);
goto cleanup;
}
}
bzero(&zerobuf, sizeof(zerobuf));
if (VIR_ALLOC_N(buf, bytes) < 0) {
virReportOOMError(conn);
goto cleanup;
}
remain = *total;
while (amtread != 0) {
int amtleft;
if (remain < bytes)
bytes = remain;
if ((amtread = saferead(inputfd, buf, bytes)) < 0) {
virReportSystemError(conn, errno,
_("failed reading from file '%s'"),
inputvol->target.path);
goto cleanup;
}
remain -= amtread;
/* Loop over amt read in 512 byte increments, looking for sparse
* blocks */
amtleft = amtread;
do {
int interval = ((512 > amtleft) ? amtleft : 512);
int offset = amtread - amtleft;
if (memcmp(buf+offset, zerobuf, interval) == 0) {
if (lseek(fd, interval, SEEK_CUR) < 0) {
virReportSystemError(conn, errno,
_("cannot extend file '%s'"),
vol->target.path);
goto cleanup;
}
} else if (safewrite(fd, buf+offset, interval) < 0) {
virReportSystemError(conn, errno,
_("failed writing to file '%s'"),
vol->target.path);
goto cleanup;
}
} while ((amtleft -= 512) > 0);
}
if (inputfd != -1 && close(inputfd) < 0) {
virReportSystemError(conn, errno,
_("cannot close file '%s'"),
inputvol->target.path);
goto cleanup;
}
inputfd = -1;
*total -= remain;
ret = 0;
cleanup:
if (inputfd != -1)
close(inputfd);
return ret;
}
int
virStorageBackendCreateRaw(virConnectPtr conn,
virStorageVolDefPtr vol,
@ -110,7 +199,6 @@ virStorageBackendCreateRaw(virConnectPtr conn,
unsigned int flags ATTRIBUTE_UNUSED)
{
int fd = -1;
int inputfd = -1;
int ret = -1;
unsigned long long remain;
char *buf = NULL;
@ -123,15 +211,6 @@ virStorageBackendCreateRaw(virConnectPtr conn,
goto cleanup;
}
if (inputvol) {
if ((inputfd = open(inputvol->target.path, O_RDONLY)) < 0) {
virReportSystemError(conn, errno,
_("could not open input path '%s'"),
inputvol->target.path);
goto cleanup;
}
}
/* Seek to the final size, so the capacity is available upfront
* for progress reporting */
if (ftruncate(fd, vol->capacity) < 0) {
@ -143,55 +222,10 @@ virStorageBackendCreateRaw(virConnectPtr conn,
remain = vol->allocation;
if (inputfd != -1) {
int amtread = -1;
size_t bytes = 1024 * 1024;
char zerobuf[512];
bzero(&zerobuf, sizeof(zerobuf));
if (VIR_ALLOC_N(buf, bytes) < 0) {
virReportOOMError(conn);
if (inputvol) {
int res = virStorageBackendCopyToFD(conn, vol, inputvol, fd, &remain);
if (res < 0)
goto cleanup;
}
while (amtread != 0) {
int amtleft;
if (remain < bytes)
bytes = remain;
if ((amtread = saferead(inputfd, buf, bytes)) < 0) {
virReportSystemError(conn, errno,
_("failed reading from file '%s'"),
inputvol->target.path);
goto cleanup;
}
remain -= amtread;
/* Loop over amt read in 512 byte increments, looking for sparse
* blocks */
amtleft = amtread;
do {
int interval = ((512 > amtleft) ? amtleft : 512);
int offset = amtread - amtleft;
if (memcmp(buf+offset, zerobuf, interval) == 0) {
if (lseek(fd, interval, SEEK_CUR) < 0) {
virReportSystemError(conn, errno,
_("cannot extend file '%s'"),
vol->target.path);
goto cleanup;
}
} else if (safewrite(fd, buf+offset, interval) < 0) {
virReportSystemError(conn, errno,
_("failed writing to file '%s'"),
vol->target.path);
goto cleanup;
}
} while ((amtleft -= 512) > 0);
}
}
if (remain) {
@ -236,20 +270,10 @@ virStorageBackendCreateRaw(virConnectPtr conn,
}
fd = -1;
if (inputfd != -1 && close(inputfd) < 0) {
virReportSystemError(conn, errno,
_("cannot close file '%s'"),
inputvol->target.path);
goto cleanup;
}
inputfd = -1;
ret = 0;
cleanup:
if (fd != -1)
close(fd);
if (inputfd != -1)
close(inputfd);
VIR_FREE(buf);
return ret;