[libvirt] [PATCH] Fix safezero()
Daniel Veillard
veillard at redhat.com
Tue Mar 2 16:48:43 UTC 2010
On Tue, Mar 02, 2010 at 04:11:24PM +0100, Jiri Denemark wrote:
> 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 at 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 */
ACK, this is bug fix from my viewpoint, so I'm fine pushing this now,
Daniel
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
daniel at veillard.com | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library http://libvirt.org/
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