[libvirt] [PATCH v3 1/5] storage: Modify storageBackendWipeLocal to allow zero from end of device
Add bool 'zero_end' and logic that would allow a caller to wipe specific
portions of a target device either from the beginning (the default) or
from the end when zero_end is true.
This will allow for this code to wipe out partition table information
from a device.
Signed-off-by: John Ferlan <jferlan(a)redhat.com>
---
src/storage/storage_util.c | 48 +++++++++++++++++++++++++++++++++-------------
1 file changed, 35 insertions(+), 13 deletions(-)
diff --git a/src/storage/storage_util.c b/src/storage/storage_util.c
index a2d89af..c1734e7 100644
--- a/src/storage/storage_util.c
+++ b/src/storage/storage_util.c
@@ -2516,24 +2516,44 @@ static int
storageBackendWipeLocal(const char *path,
int fd,
unsigned long long wipe_len,
- size_t writebuf_length)
+ size_t writebuf_length,
+ bool zero_end)
{
int ret = -1, written = 0;
unsigned long long remaining = 0;
+ off_t size;
size_t write_size = 0;
char *writebuf = NULL;
- VIR_DEBUG("wiping start: 0 len: %llu", wipe_len);
-
if (VIR_ALLOC_N(writebuf, writebuf_length) < 0)
goto cleanup;
- if (lseek(fd, 0, SEEK_SET) < 0) {
- virReportSystemError(errno,
- _("Failed to seek to the start in volume "
- "with path '%s'"),
- path);
- goto cleanup;
+ if (!zero_end) {
+ if (lseek(fd, 0, SEEK_SET) < 0) {
+ virReportSystemError(errno,
+ _("Failed to seek to the start in volume "
+ "with path '%s'"),
+ path);
+ goto cleanup;
+ }
+ VIR_DEBUG("wiping start: 0 len: %llu", wipe_len);
+ } else {
+ if ((size = lseek(fd, 0, SEEK_END)) == (off_t)-1) {
+ virReportSystemError(errno,
+ _("Failed to seek to the end in volume "
+ "with path '%s'"),
+ path);
+ goto cleanup;
+ }
+ size -= wipe_len;
+ if (lseek(fd, size, SEEK_SET) < 0) {
+ virReportSystemError(errno,
+ _("Failed to seek to %zd bytes in volume "
+ "with path '%s'"),
+ size, path);
+ goto cleanup;
+ }
+ VIR_DEBUG("wiping start: %zd len: %llu", size, wipe_len);
}
remaining = wipe_len;
@@ -2573,7 +2593,8 @@ storageBackendWipeLocal(const char *path,
static int
storageBackendVolWipeLocalFile(const char *path,
unsigned int algorithm,
- unsigned long long allocation)
+ unsigned long long allocation,
+ bool zero_end)
{
int ret = -1, fd = -1;
const char *alg_char = NULL;
@@ -2648,7 +2669,8 @@ storageBackendVolWipeLocalFile(const char *path,
if (S_ISREG(st.st_mode) && st.st_blocks < (st.st_size / DEV_BSIZE)) {
ret = storageBackendVolZeroSparseFileLocal(path, st.st_size, fd);
} else {
- ret = storageBackendWipeLocal(path, fd, allocation, st.st_blksize);
+ ret = storageBackendWipeLocal(path, fd, allocation, st.st_blksize,
+ zero_end);
}
if (ret < 0)
goto cleanup;
@@ -2686,7 +2708,7 @@ storageBackendVolWipePloop(virStorageVolDefPtr vol,
goto cleanup;
if (storageBackendVolWipeLocalFile(target_path, algorithm,
- vol->target.allocation) < 0)
+ vol->target.allocation, false) < 0)
goto cleanup;
if (virFileRemove(disk_desc, 0, 0) < 0) {
@@ -2735,7 +2757,7 @@ virStorageBackendVolWipeLocal(virConnectPtr conn ATTRIBUTE_UNUSED,
ret = storageBackendVolWipePloop(vol, algorithm);
} else {
ret = storageBackendVolWipeLocalFile(vol->target.path, algorithm,
- vol->target.allocation);
+ vol->target.allocation, false);
}
return ret;
--
2.9.3