path: root/tools/hv/hv_vss_daemon.c
diff options
authorAlex Ng <alexng@messages.microsoft.com>2017-08-06 13:12:52 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-08-16 09:14:42 -0700
commitea81fdf0981d9a4a998a015d325bed67624811f7 (patch)
treeca2364878d9f65a4472f3ae4a658b69a570ee093 /tools/hv/hv_vss_daemon.c
parent5f972797b1b97ab94ef48188321bff6cc190a2e0 (diff)
Tools: hv: vss: Skip freezing filesystems backed by loop
Since a loop device is backed by a file, a backup will already result in its parent filesystem being frozen. It's sufficient to just freeze the parent filesystem, so we can skip the loop device. This avoids a situation where a loop device and its parent filesystem are both frozen and then thawed out of order. For example, if the loop device is enumerated first, we would thaw it while its parent filesystem is still frozen. The thaw operation fails and the loop device remains frozen. Signed-off-by: Alex Ng <alexng@messages.microsoft.com> Signed-off-by: Vyronas Tsingaras <vyronas@vtsingaras.me> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/hv/hv_vss_daemon.c')
1 files changed, 7 insertions, 0 deletions
diff --git a/tools/hv/hv_vss_daemon.c b/tools/hv/hv_vss_daemon.c
index 7ba54195934c..b2b4ebffab8c 100644
--- a/tools/hv/hv_vss_daemon.c
+++ b/tools/hv/hv_vss_daemon.c
@@ -21,6 +21,7 @@
#include <sys/types.h>
#include <sys/poll.h>
#include <sys/ioctl.h>
+#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <mntent.h>
@@ -30,6 +31,7 @@
#include <ctype.h>
#include <errno.h>
#include <linux/fs.h>
+#include <linux/major.h>
#include <linux/hyperv.h>
#include <syslog.h>
#include <getopt.h>
@@ -70,6 +72,7 @@ static int vss_operate(int operation)
char match[] = "/dev/";
FILE *mounts;
struct mntent *ent;
+ struct stat sb;
char errdir[1024] = {0};
unsigned int cmd;
int error = 0, root_seen = 0, save_errno = 0;
@@ -92,6 +95,10 @@ static int vss_operate(int operation)
while ((ent = getmntent(mounts))) {
if (strncmp(ent->mnt_fsname, match, strlen(match)))
+ if (stat(ent->mnt_fsname, &sb) == -1)
+ continue;
+ if (S_ISBLK(sb.st_mode) && major(sb.st_rdev) == LOOP_MAJOR)
+ continue;
if (hasmntopt(ent, MNTOPT_RO) != NULL)
if (strcmp(ent->mnt_type, "vfat") == 0)