From f20c2a3298ceae7536c06bd08a5c571ebfa8cce4 Mon Sep 17 00:00:00 2001

From: Miroslav Rezanina <mrezanin@redhat.com>

Date: Thu, 6 May 2021 12:50:43 +0200

Subject: Update C files and scripts to kernel version 5.7-rc1

(cherry-picked from RHEL 8.4.0 commit b0a20fac0e74b0b3eecc20ffe74006e7877da352)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 hv_fcopy_daemon.c   | 37 +++++++++++++++++++++++++++++++-----

 hv_get_dhcp_info.sh |  2 +-

 hv_kvp_daemon.c     | 35 ++++++++++++++++++++--------------

 hv_set_ifconfig.sh  |  2 +-

 hv_vss_daemon.c     | 46 ++++++++++++++++++++++++++++++++++-----------

 5 files changed, 90 insertions(+), 32 deletions(-)

diff --git a/hv_fcopy_daemon.c b/hv_fcopy_daemon.c

index aea2d91..16d629b 100644

--- a/hv_fcopy_daemon.c

+++ b/hv_fcopy_daemon.c

@@ -80,6 +80,8 @@ static int hv_start_fcopy(struct hv_start_fcopy *smsg)

 	error = 0;

 done:

+	if (error)

+		target_fname[0] = '\0';

 	return error;

 }

@@ -108,15 +110,29 @@ static int hv_copy_data(struct hv_do_fcopy *cpmsg)

 	return ret;

 }

+/*

+ * Reset target_fname to "" in the two below functions for hibernation: if

+ * the fcopy operation is aborted by hibernation, the daemon should remove the

+ * partially-copied file; to achieve this, the hv_utils driver always fakes a

+ * CANCEL_FCOPY message upon suspend, and later when the VM resumes back,

+ * the daemon calls hv_copy_cancel() to remove the file; if a file is copied

+ * successfully before suspend, hv_copy_finished() must reset target_fname to

+ * avoid that the file can be incorrectly removed upon resume, since the faked

+ * CANCEL_FCOPY message is spurious in this case.

+ */

 static int hv_copy_finished(void)

 {

 	close(target_fd);

+	target_fname[0] = '\0';

 	return 0;

 }

 static int hv_copy_cancel(void)

 {

 	close(target_fd);

-	unlink(target_fname);

+	if (strlen(target_fname) > 0) {

+		unlink(target_fname);

+		target_fname[0] = '\0';

+	}

 	return 0;

 }

@@ -131,7 +147,7 @@ void print_usage(char *argv[])

 int main(int argc, char *argv[])

 {

-	int fcopy_fd;

+	int fcopy_fd = -1;

 	int error;

 	int daemonize = 1, long_index = 0, opt;

 	int version = FCOPY_CURRENT_VERSION;

@@ -141,7 +157,7 @@ int main(int argc, char *argv[])

 		struct hv_do_fcopy copy;

 		__u32 kernel_modver;

 	} buffer = { };

-	int in_handshake = 1;

+	int in_handshake;

 	static struct option long_options[] = {

 		{"help",	no_argument,	   0,  'h' },

@@ -170,6 +186,12 @@ int main(int argc, char *argv[])

 	openlog("HV_FCOPY", 0, LOG_USER);

 	syslog(LOG_INFO, "starting; pid is:%d", getpid());

+reopen_fcopy_fd:

+	if (fcopy_fd != -1)

+		close(fcopy_fd);

+	/* Remove any possible partially-copied file on error */

+	hv_copy_cancel();

+	in_handshake = 1;

 	fcopy_fd = open("/dev/vmbus/hv_fcopy", O_RDWR);

 	if (fcopy_fd < 0) {

@@ -196,7 +218,7 @@ int main(int argc, char *argv[])

 		len = pread(fcopy_fd, &buffer, sizeof(buffer), 0);

 		if (len < 0) {

 			syslog(LOG_ERR, "pread failed: %s", strerror(errno));

-			exit(EXIT_FAILURE);

+			goto reopen_fcopy_fd;

 		}

 		if (in_handshake) {

@@ -231,9 +253,14 @@ int main(int argc, char *argv[])

 		}

+		/*

+		 * pwrite() may return an error due to the faked CANCEL_FCOPY

+		 * message upon hibernation. Ignore the error by resetting the

+		 * dev file, i.e. closing and re-opening it.

+		 */

 		if (pwrite(fcopy_fd, &error, sizeof(int), 0) != sizeof(int)) {

 			syslog(LOG_ERR, "pwrite failed: %s", strerror(errno));

-			exit(EXIT_FAILURE);

+			goto reopen_fcopy_fd;

 		}

 	}

 }

diff --git a/hv_get_dhcp_info.sh b/hv_get_dhcp_info.sh

index c38686c..2f2a3c7 100644

--- a/hv_get_dhcp_info.sh

+++ b/hv_get_dhcp_info.sh

@@ -13,7 +13,7 @@

 #	the script prints the string "Disabled" to stdout.

 #

 # Each Distro is expected to implement this script in a distro specific

-# fashion. For instance on Distros that ship with Network Manager enabled,

+# fashion. For instance, on Distros that ship with Network Manager enabled,

 # this script can be based on the Network Manager APIs for retrieving DHCP

 # information.

diff --git a/hv_kvp_daemon.c b/hv_kvp_daemon.c

index e9ef4ca..0e5f14a 100644

--- a/hv_kvp_daemon.c

+++ b/hv_kvp_daemon.c

@@ -76,7 +76,7 @@ enum {

 	DNS

 };

-static int in_hand_shake = 1;

+static int in_hand_shake;

 static char *os_name = "";

 static char *os_major = "";

@@ -1360,7 +1360,7 @@ void print_usage(char *argv[])

 int main(int argc, char *argv[])

 {

-	int kvp_fd, len;

+	int kvp_fd = -1, len;

 	int error;

 	struct pollfd pfd;

 	char    *p;

@@ -1400,14 +1400,6 @@ int main(int argc, char *argv[])

 	openlog("KVP", 0, LOG_USER);

 	syslog(LOG_INFO, "KVP starting; pid is:%d", getpid());

-	kvp_fd = open("/dev/vmbus/hv_kvp", O_RDWR | O_CLOEXEC);

-

-	if (kvp_fd < 0) {

-		syslog(LOG_ERR, "open /dev/vmbus/hv_kvp failed; error: %d %s",

-			errno, strerror(errno));

-		exit(EXIT_FAILURE);

-	}

-

 	/*

 	 * Retrieve OS release information.

 	 */

@@ -1423,6 +1415,18 @@ int main(int argc, char *argv[])

 		exit(EXIT_FAILURE);

 	}

+reopen_kvp_fd:

+	if (kvp_fd != -1)

+		close(kvp_fd);

+	in_hand_shake = 1;

+	kvp_fd = open("/dev/vmbus/hv_kvp", O_RDWR | O_CLOEXEC);

+

+	if (kvp_fd < 0) {

+		syslog(LOG_ERR, "open /dev/vmbus/hv_kvp failed; error: %d %s",

+		       errno, strerror(errno));

+		exit(EXIT_FAILURE);

+	}

+

 	/*

 	 * Register ourselves with the kernel.

 	 */

@@ -1457,8 +1461,7 @@ int main(int argc, char *argv[])

 			syslog(LOG_ERR, "read failed; error:%d %s",

 			       errno, strerror(errno));

-			close(kvp_fd);

-			return EXIT_FAILURE;

+			goto reopen_kvp_fd;

 		}

 		/*

@@ -1617,13 +1620,17 @@ int main(int argc, char *argv[])

 			break;

 		}

-		/* Send the value back to the kernel. */

+		/*

+		 * Send the value back to the kernel. Note: the write() may

+		 * return an error due to hibernation; we can ignore the error

+		 * by resetting the dev file, i.e. closing and re-opening it.

+		 */

 kvp_done:

 		len = write(kvp_fd, hv_msg, sizeof(struct hv_kvp_msg));

 		if (len != sizeof(struct hv_kvp_msg)) {

 			syslog(LOG_ERR, "write failed; error: %d %s", errno,

 			       strerror(errno));

-			exit(EXIT_FAILURE);

+			goto reopen_kvp_fd;

 		}

 	}

diff --git a/hv_set_ifconfig.sh b/hv_set_ifconfig.sh

index 18b27cc..3dd064c 100644

--- a/hv_set_ifconfig.sh

+++ b/hv_set_ifconfig.sh

@@ -12,7 +12,7 @@

 # be used to configure the interface.

 #

 # Each Distro is expected to implement this script in a distro specific

-# fashion. For instance on Distros that ship with Network Manager enabled,

+# fashion. For instance, on Distros that ship with Network Manager enabled,

 # this script can be based on the Network Manager APIs for configuring the

 # interface.

 #

diff --git a/hv_vss_daemon.c b/hv_vss_daemon.c

index 92902a8..29a1e48 100644

--- a/hv_vss_daemon.c

+++ b/hv_vss_daemon.c

@@ -28,6 +28,8 @@

 #include <stdbool.h>

 #include <dirent.h>

+static bool fs_frozen;

+

 /* Don't use syslog() in the function since that can cause write to disk */

 static int vss_do_freeze(char *dir, unsigned int cmd)

 {

@@ -155,16 +157,22 @@ static int vss_operate(int operation)

 			continue;

 		}

 		error |= vss_do_freeze(ent->mnt_dir, cmd);

-		if (error && operation == VSS_OP_FREEZE)

-			goto err;

+		if (operation == VSS_OP_FREEZE) {

+			if (error)

+				goto err;

+			fs_frozen = true;

+		}

 	}

 	endmntent(mounts);

 	if (root_seen) {

 		error |= vss_do_freeze("/", cmd);

-		if (error && operation == VSS_OP_FREEZE)

-			goto err;

+		if (operation == VSS_OP_FREEZE) {

+			if (error)

+				goto err;

+			fs_frozen = true;

+		}

 	}

 	goto out;

@@ -175,6 +183,7 @@ err:

 		endmntent(mounts);

 	}

 	vss_operate(VSS_OP_THAW);

+	fs_frozen = false;

 	/* Call syslog after we thaw all filesystems */

 	if (ent)

 		syslog(LOG_ERR, "FREEZE of %s failed; error:%d %s",

@@ -196,13 +205,13 @@ void print_usage(char *argv[])

 int main(int argc, char *argv[])

 {

-	int vss_fd, len;

+	int vss_fd = -1, len;

 	int error;

 	struct pollfd pfd;

 	int	op;

 	struct hv_vss_msg vss_msg[1];

 	int daemonize = 1, long_index = 0, opt;

-	int in_handshake = 1;

+	int in_handshake;

 	__u32 kernel_modver;

 	static struct option long_options[] = {

@@ -232,6 +241,18 @@ int main(int argc, char *argv[])

 	openlog("Hyper-V VSS", 0, LOG_USER);

 	syslog(LOG_INFO, "VSS starting; pid is:%d", getpid());

+reopen_vss_fd:

+	if (vss_fd != -1)

+		close(vss_fd);

+	if (fs_frozen) {

+		if (vss_operate(VSS_OP_THAW) || fs_frozen) {

+			syslog(LOG_ERR, "failed to thaw file system: err=%d",

+			       errno);

+			exit(EXIT_FAILURE);

+		}

+	}

+

+	in_handshake = 1;

 	vss_fd = open("/dev/vmbus/hv_vss", O_RDWR);

 	if (vss_fd < 0) {

 		syslog(LOG_ERR, "open /dev/vmbus/hv_vss failed; error: %d %s",

@@ -247,8 +268,7 @@ int main(int argc, char *argv[])

 	if (len < 0) {

 		syslog(LOG_ERR, "registration to kernel failed; error: %d %s",

 		       errno, strerror(errno));

-		close(vss_fd);

-		exit(EXIT_FAILURE);

+		goto reopen_vss_fd;

 	}

 	pfd.fd = vss_fd;

@@ -312,14 +332,18 @@ int main(int argc, char *argv[])

 		default:

 			syslog(LOG_ERR, "Illegal op:%d\n", op);

 		}

+

+		/*

+		 * The write() may return an error due to the faked VSS_OP_THAW

+		 * message upon hibernation. Ignore the error by resetting the

+		 * dev file, i.e. closing and re-opening it.

+		 */

 		vss_msg->error = error;

 		len = write(vss_fd, vss_msg, sizeof(struct hv_vss_msg));

 		if (len != sizeof(struct hv_vss_msg)) {

 			syslog(LOG_ERR, "write failed; error: %d %s", errno,

 			       strerror(errno));

-

-			if (op == VSS_OP_FREEZE)

-				vss_operate(VSS_OP_THAW);

+			goto reopen_vss_fd;

 		}

 	}

-- 

2.27.0