From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Liu Subject: [PATCH] libvhd: use UTC for VHD timestamp Date: Fri, 30 Aug 2013 14:07:20 +0100 Message-ID: <1377868040-13668-1-git-send-email-wei.liu2@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org Cc: Wei Liu , ian.jackson@eu.citrix.com, Andrei Lifchits List-Id: xen-devel@lists.xenproject.org [ported from xapi-project/blktap a79ac2c05f9 ("XOP-289: use UTC for VHD timestamps")] Currently, the local timezone is factored into VHD timestamps due to the use of mktime(). This breaks "vhd-util check" for VHDs created in one timezone and then moved westward, which results in "primary footer invalid: creation time in future" errors. Signed-off-by: Andrei Lifchits --- Add SoB for Andrei Lifchits. Remove unused variable "tm". Signed-off-by: Wei Liu --- tools/blktap2/vhd/lib/libvhd.c | 33 +++++++++------------------------ 1 file changed, 9 insertions(+), 24 deletions(-) diff --git a/tools/blktap2/vhd/lib/libvhd.c b/tools/blktap2/vhd/lib/libvhd.c index 3511cb4..95eb5d6 100644 --- a/tools/blktap2/vhd/lib/libvhd.c +++ b/tools/blktap2/vhd/lib/libvhd.c @@ -41,6 +41,10 @@ #include "libvhd.h" #include "relative-path.h" +/* VHD uses an epoch of 12:00AM, Jan 1, 2000. This is the Unix timestamp for + * the start of the VHD epoch. */ +#define VHD_EPOCH_START 946684800 + static int libvhd_dbg = 0; void @@ -694,19 +698,10 @@ vhd_end_of_data(vhd_context_t *ctx, off_t *end) return 0; } -uint32_t +uint32_t inline vhd_time(time_t time) { - struct tm tm; - time_t micro_epoch; - - memset(&tm, 0, sizeof(struct tm)); - tm.tm_year = 100; - tm.tm_mon = 0; - tm.tm_mday = 1; - micro_epoch = mktime(&tm); - - return (uint32_t)(time - micro_epoch); + return (uint32_t)(time - VHD_EPOCH_START); } /* @@ -717,20 +712,10 @@ size_t vhd_time_to_string(uint32_t timestamp, char *target) { char *cr; - struct tm tm; - time_t t1, t2; - - memset(&tm, 0, sizeof(struct tm)); - - /* VHD uses an epoch of 12:00AM, Jan 1, 2000. */ - /* Need to adjust this to the expected epoch of 1970. */ - tm.tm_year = 100; - tm.tm_mon = 0; - tm.tm_mday = 1; + time_t unix_timestamp; - t1 = mktime(&tm); - t2 = t1 + (time_t)timestamp; - ctime_r(&t2, target); + unix_timestamp = (time_t)timestamp + VHD_EPOCH_START; + ctime_r(&unix_timestamp, target); /* handle mad ctime_r newline appending. */ if ((cr = strchr(target, '\n')) != NULL) -- 1.7.10.4