[libvirt] [PATCH] Fix safezero()
Various safezero() implementations used either -1, errno or -errno
return values. This patch fixes them all to return -1 and set errno
appropriately.
There was also a bug in size parameter passed to safewrite() which could
result in an attempt to write gigabytes out of a megabyte buffer.
Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com>
---
src/storage/storage_backend.c | 4 ++--
src/util/util.c | 16 +++++++++-------
2 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c
index 3742493..849f01b 100644
--- a/src/storage/storage_backend.c
+++ b/src/storage/storage_backend.c
@@ -316,7 +316,7 @@ static int createRawFileOpHook(int fd, void *data) {
if ((r = safezero(fd, 0, hdata->vol->allocation - remain,
bytes)) != 0) {
ret = errno;
- virReportSystemError(r, _("cannot fill file
'%s'"),
+ virReportSystemError(errno, _("cannot fill file
'%s'"),
hdata->vol->target.path);
goto cleanup;
}
@@ -327,7 +327,7 @@ static int createRawFileOpHook(int fd, void *data) {
if ((r = safezero(fd, 0, 0, remain)) != 0) {
ret = errno;
- virReportSystemError(r, _("cannot fill file '%s'"),
+ virReportSystemError(errno, _("cannot fill file
'%s'"),
hdata->vol->target.path);
goto cleanup;
}
diff --git a/src/util/util.c b/src/util/util.c
index cf7bba5..34c585d 100644
--- a/src/util/util.c
+++ b/src/util/util.c
@@ -146,11 +146,11 @@ int safezero(int fd, int flags ATTRIBUTE_UNUSED, off_t offset, off_t
len)
*/
r = ftruncate(fd, offset + len);
if (r < 0)
- return -errno;
+ return -1;
buf = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, offset);
if (buf == MAP_FAILED)
- return -errno;
+ return -1;
memset(buf, 0, len);
munmap(buf, len);
@@ -167,24 +167,26 @@ int safezero(int fd, int flags ATTRIBUTE_UNUSED, off_t offset, off_t
len)
unsigned long long remain, bytes;
if (lseek(fd, offset, SEEK_SET) < 0)
- return errno;
+ return -1;
/* Split up the write in small chunks so as not to allocate lots of RAM */
remain = len;
bytes = 1024 * 1024;
r = VIR_ALLOC_N(buf, bytes);
- if (r < 0)
- return -ENOMEM;
+ if (r < 0) {
+ errno = ENOMEM;
+ return -1;
+ }
while (remain) {
if (bytes > remain)
bytes = remain;
- r = safewrite(fd, buf, len);
+ r = safewrite(fd, buf, bytes);
if (r < 0) {
VIR_FREE(buf);
- return r;
+ return -1;
}
/* safewrite() guarantees all data will be written */
--
1.7.0