From: kys@exchange.microsoft.com
To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
        devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com,
        vkuznets@redhat.com, jasowang@redhat.com,
        leann.ogasawara@canonical.com, marcelo.cerri@canonical.com,
        sthemmin@microsoft.com
Cc: Alex Ng <alexng@messages.microsoft.com>,
        Vyronas Tsingaras <vyronas@vtsingaras.me>,
        "K. Y. Srinivasan" <kys@microsoft.com>
Subject: [PATCH 1/2] Tools: hv: vss: Skip freezing filesystems backed by loop
Date: Sun, 25 Jun 2017 12:47:45 -0700
Message-Id: <1498420066-5000-1-git-send-email-kys@exchange.microsoft.com>
In-Reply-To: <1498420033-4914-1-git-send-email-kys@exchange.microsoft.com>
References: <1498420033-4914-1-git-send-email-kys@exchange.microsoft.com>
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Sender: linux-kernel-owner@vger.kernel.org
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From: Alex Ng <alexng@messages.microsoft.com>

Skip loop devices from the freeze/thaw operation.

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>
---
 tools/hv/hv_vss_daemon.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/tools/hv/hv_vss_daemon.c b/tools/hv/hv_vss_daemon.c
index 7ba5419..b2b4ebf 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)))
 			continue;
+		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)
 			continue;
 		if (strcmp(ent->mnt_type, "vfat") == 0)
-- 
1.7.1