[PATCH v3 0/6] VDUSE reconnection fixes and cleanup

[PATCH v3 0/6] VDUSE reconnection fixes and cleanup

[Maxime Coquelin]

This series provides various fixes for VDUSE reconnection
introduced in -rc1, some of them being reported by
Coverity.

The series also takes the opportunity to refactor
reconnection to make it more self-contained to simplify
readability and error path handling.

Changes in v2:
==============
- Avoid superluous error logging (David)
- VDUSE in capital letter in commit title 1 (David)
- Declare dev_config in the code block it is used (David)
- Fix wrong goto in intermediate patch (Maxime)

Maxime Coquelin (6):
  vhost: fix VDUSE device creation error handling
  vhost: fix possible TOCTOU in VDUSE dev creation
  vhost: fix VDUSE reconnect device start failure
  vhost: refactor VDUSE reconnection log mapping
  vhost: fix and refactor VDUSE reconnect log check
  vhost: move VDUSE reconnection after device is created

 lib/vhost/vduse.c | 322 ++++++++++++++++++++++++++--------------------
 1 file changed, 181 insertions(+), 141 deletions(-)

-- 
2.46.2

[PATCH v3 1/6] vhost: fix VDUSE device creation error handling

[Maxime Coquelin]

This patch fixes missing reconnection log unmapping
miss in the error path at VDUSE creation time.

Coverity issue: 445525
Fixes: da79cc7fda76 ("vhost: add reconnection support to VDUSE")

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/vduse.c | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
index f9ac317438..4bb309e441 100644
--- a/lib/vhost/vduse.c
+++ b/lib/vhost/vduse.c
@@ -485,10 +485,9 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 	struct virtio_net_config vnet_config = {{ 0 }};
 	uint64_t ver = VHOST_VDUSE_API_VERSION;
 	uint64_t features;
-	struct vduse_dev_config *dev_config = NULL;
 	const char *name = path + strlen("/dev/vduse/");
 	char reconnect_file[PATH_MAX];
-	struct vhost_reconnect_data *reconnect_log = NULL;
+	struct vhost_reconnect_data *reconnect_log = MAP_FAILED;
 	bool reconnect = false;
 
 	if (vduse.fdset == NULL) {
@@ -530,13 +529,13 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 	ret = rte_vhost_driver_get_features(path, &features);
 	if (ret < 0) {
 		VHOST_CONFIG_LOG(name, ERR, "Failed to get backend features");
-		goto out_free;
+		goto out_ctrl_close;
 	}
 
 	ret = rte_vhost_driver_get_queue_num(path, &max_queue_pairs);
 	if (ret < 0) {
 		VHOST_CONFIG_LOG(name, ERR, "Failed to get max queue pairs");
-		goto out_free;
+		goto out_ctrl_close;
 	}
 
 	VHOST_CONFIG_LOG(path, INFO, "VDUSE max queue pairs: %u", max_queue_pairs);
@@ -584,7 +583,7 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 					"Features mismatch between backend (0x%" PRIx64 ") & reconnection file (0x%" PRIx64 ")",
 					features, reconnect_log->features);
 			ret = -1;
-			goto out_ctrl_close;
+			goto out_log_unmap;
 		}
 
 		if (reconnect_log->nr_vrings != total_queues) {
@@ -592,9 +591,11 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 					"Queues number mismatch between backend (%u) and reconnection file (%u)",
 					total_queues, reconnect_log->nr_vrings);
 			ret = -1;
-			goto out_ctrl_close;
+			goto out_log_unmap;
 		}
 	} else {
+		struct vduse_dev_config *dev_config;
+
 		reco_fd = open(reconnect_file, O_CREAT | O_EXCL | O_RDWR, 0600);
 		if (reco_fd < 0) {
 			if (errno == EEXIST) {
@@ -633,7 +634,7 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 		if (!dev_config) {
 			VHOST_CONFIG_LOG(name, ERR, "Failed to allocate VDUSE config");
 			ret = -1;
-			goto out_ctrl_close;
+			goto out_log_unmap;
 		}
 
 		vnet_config.max_virtqueue_pairs = max_queue_pairs;
@@ -649,16 +650,16 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 		memcpy(dev_config->config, &vnet_config, sizeof(vnet_config));
 
 		ret = ioctl(control_fd, VDUSE_CREATE_DEV, dev_config);
+		free(dev_config);
+		dev_config = NULL;
 		if (ret < 0) {
 			VHOST_CONFIG_LOG(name, ERR, "Failed to create VDUSE device: %s",
 					strerror(errno));
-			goto out_free;
+			goto out_log_unmap;
 		}
 
 		memcpy(&reconnect_log->config, &vnet_config, sizeof(vnet_config));
 		reconnect_log->nr_vrings = total_queues;
-		free(dev_config);
-		dev_config = NULL;
 	}
 
 	dev_fd = open(path, O_RDWR);
@@ -693,6 +694,7 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 	dev->vduse_ctrl_fd = control_fd;
 	dev->vduse_dev_fd = dev_fd;
 	dev->reconnect_log = reconnect_log;
+	reconnect_log = MAP_FAILED;
 	if (reconnect)
 		dev->status = dev->reconnect_log->status;
 
@@ -768,8 +770,9 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 	if (dev_fd >= 0)
 		close(dev_fd);
 	ioctl(control_fd, VDUSE_DESTROY_DEV, name);
-out_free:
-	free(dev_config);
+out_log_unmap:
+	if (reconnect_log != MAP_FAILED)
+		munmap(reconnect_log, sizeof(*reconnect_log));
 out_ctrl_close:
 	close(control_fd);
 
-- 
2.46.2

[PATCH v3 2/6] vhost: fix possible TOCTOU in VDUSE dev creation

[Maxime Coquelin]

This patch fixes a possible TOCTOU on the VDUSE
device chardev opening at device creation time.

Coverity issue: 445526
Fixes: da79cc7fda76 ("vhost: add reconnection support to VDUSE")

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>
---
 lib/vhost/vduse.c | 34 ++++++++++++++++++++--------------
 1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
index 4bb309e441..a98b33dddf 100644
--- a/lib/vhost/vduse.c
+++ b/lib/vhost/vduse.c
@@ -546,7 +546,8 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 	else
 		total_queues += 1; /* Includes ctrl queue */
 
-	if (access(path, F_OK) == 0) {
+	dev_fd = open(path, O_RDWR);
+	if (dev_fd >= 0) {
 		VHOST_CONFIG_LOG(name, INFO, "Device already exists, reconnecting...");
 		reconnect = true;
 
@@ -559,7 +560,7 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 				VHOST_CONFIG_LOG(name, ERR, "Failed to open reconnect file %s (%s)",
 						reconnect_file, strerror(errno));
 			ret = -1;
-			goto out_ctrl_close;
+			goto out_dev_close;
 		}
 
 		reconnect_log = mmap(NULL, sizeof(*reconnect_log), PROT_READ | PROT_WRITE,
@@ -569,7 +570,7 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 			VHOST_CONFIG_LOG(name, ERR, "Failed to mmap reconnect file %s (%s)",
 					reconnect_file, strerror(errno));
 			ret = -1;
-			goto out_ctrl_close;
+			goto out_dev_close;
 		}
 
 		if (reconnect_log->version != VHOST_RECONNECT_VERSION) {
@@ -593,7 +594,7 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 			ret = -1;
 			goto out_log_unmap;
 		}
-	} else {
+	} else if (errno == ENOENT) {
 		struct vduse_dev_config *dev_config;
 
 		reco_fd = open(reconnect_file, O_CREAT | O_EXCL | O_RDWR, 0600);
@@ -660,34 +661,39 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 
 		memcpy(&reconnect_log->config, &vnet_config, sizeof(vnet_config));
 		reconnect_log->nr_vrings = total_queues;
-	}
 
-	dev_fd = open(path, O_RDWR);
-	if (dev_fd < 0) {
+		dev_fd = open(path, O_RDWR);
+		if (dev_fd < 0) {
+			VHOST_CONFIG_LOG(name, ERR, "Failed to open newly created device %s: %s",
+					path, strerror(errno));
+			ret = -1;
+			goto out_log_unmap;
+		}
+	} else {
 		VHOST_CONFIG_LOG(name, ERR, "Failed to open device %s: %s",
 				path, strerror(errno));
 		ret = -1;
-		goto out_dev_close;
+		goto out_ctrl_close;
 	}
 
 	ret = fcntl(dev_fd, F_SETFL, O_NONBLOCK);
 	if (ret < 0) {
 		VHOST_CONFIG_LOG(name, ERR, "Failed to set chardev as non-blocking: %s",
 				strerror(errno));
-		goto out_dev_close;
+		goto out_log_unmap;
 	}
 
 	vid = vhost_new_device(&vduse_backend_ops);
 	if (vid < 0) {
 		VHOST_CONFIG_LOG(name, ERR, "Failed to create new Vhost device");
 		ret = -1;
-		goto out_dev_close;
+		goto out_log_unmap;
 	}
 
 	dev = get_device(vid);
 	if (!dev) {
 		ret = -1;
-		goto out_dev_close;
+		goto out_dev_destroy;
 	}
 
 	strncpy(dev->ifname, path, IF_NAME_SZ - 1);
@@ -766,13 +772,13 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 
 out_dev_destroy:
 	vhost_destroy_device(vid);
+out_log_unmap:
+	if (reconnect_log != MAP_FAILED)
+		munmap(reconnect_log, sizeof(*reconnect_log));
 out_dev_close:
 	if (dev_fd >= 0)
 		close(dev_fd);
 	ioctl(control_fd, VDUSE_DESTROY_DEV, name);
-out_log_unmap:
-	if (reconnect_log != MAP_FAILED)
-		munmap(reconnect_log, sizeof(*reconnect_log));
 out_ctrl_close:
 	close(control_fd);
 
-- 
2.46.2

[PATCH v3 3/6] vhost: fix VDUSE reconnect device start failure

[Maxime Coquelin]

This patch fixes a FD leak in the VDUSE device reconnect
code fails to start the device.

Also take the opportunity to refactor the related code into
a dedicated function.

Fixes: da79cc7fda76 ("vhost: add reconnection support to VDUSE")

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/vduse.c | 65 ++++++++++++++++++++++++++++++-----------------
 1 file changed, 42 insertions(+), 23 deletions(-)

diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
index a98b33dddf..346e6795f4 100644
--- a/lib/vhost/vduse.c
+++ b/lib/vhost/vduse.c
@@ -476,6 +476,46 @@ vduse_reconnect_handler(int fd, void *arg, int *remove)
 	*remove = 1;
 }
 
+static int
+vduse_reconnect_start_device(struct virtio_net *dev)
+{
+	int fd, ret;
+
+	/*
+	 * Make vduse_device_start() being executed in the same
+	 * context for both reconnection and fresh startup.
+	 */
+	fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
+	if (fd < 0) {
+		VHOST_CONFIG_LOG(dev->ifname, ERR, "Failed to create reconnect efd: %s",
+				strerror(errno));
+		ret = -1;
+		goto out_err;
+	}
+
+	ret = fdset_add(vduse.fdset, fd, vduse_reconnect_handler, NULL, dev);
+	if (ret) {
+		VHOST_CONFIG_LOG(dev->ifname, ERR, "Failed to add reconnect efd %d to vduse fdset",
+				fd);
+		goto out_err_close;
+	}
+
+	ret = eventfd_write(fd, (eventfd_t)1);
+	if (ret < 0) {
+		VHOST_CONFIG_LOG(dev->ifname, ERR, "Failed to write to reconnect eventfd");
+		goto out_err_fdset;
+	}
+
+	return 0;
+
+out_err_fdset:
+	fdset_del(vduse.fdset, fd);
+out_err_close:
+	close(fd);
+out_err:
+	return ret;
+}
+
 int
 vduse_device_create(const char *path, bool compliant_ol_flags)
 {
@@ -742,30 +782,9 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 	}
 
 	if (reconnect && dev->status & VIRTIO_DEVICE_STATUS_DRIVER_OK)  {
-		/*
-		 * Make vduse_device_start() being executed in the same
-		 * context for both reconnection and fresh startup.
-		 */
-		reco_fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
-		if (reco_fd < 0) {
-			VHOST_CONFIG_LOG(name, ERR, "Failed to create reco_fd: %s",
-					strerror(errno));
-			ret = -1;
+		ret = vduse_reconnect_start_device(dev);
+		if (ret)
 			goto out_dev_destroy;
-		}
-
-		ret = fdset_add(vduse.fdset, reco_fd, vduse_reconnect_handler, NULL, dev);
-		if (ret) {
-			VHOST_CONFIG_LOG(name, ERR, "Failed to add reconnect fd %d to vduse fdset",
-					reco_fd);
-			goto out_dev_destroy;
-		}
-
-		ret = eventfd_write(reco_fd, (eventfd_t)1);
-		if (ret < 0) {
-			VHOST_CONFIG_LOG(name, ERR, "Failed to write to reconnect eventfd");
-			goto out_dev_destroy;
-		}
 	}
 
 	return 0;
-- 
2.46.2

[PATCH v3 4/6] vhost: refactor VDUSE reconnection log mapping

[Maxime Coquelin]

This patch moves the VDUSE reconnection log mapping, as
well as creation if needed, into a dedicated function.

This is a preliminary rework to simplify VDUSE device
creation.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/vduse.c | 138 ++++++++++++++++++++++++----------------------
 1 file changed, 73 insertions(+), 65 deletions(-)

diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
index 346e6795f4..aae20dfc55 100644
--- a/lib/vhost/vduse.c
+++ b/lib/vhost/vduse.c
@@ -431,6 +431,9 @@ vduse_reconnect_path_init(void)
 	const char *directory;
 	int ret;
 
+	if (vduse_reconnect_path_set == true)
+		return 0;
+
 	/* from RuntimeDirectory= see systemd.exec */
 	directory = getenv("RUNTIME_DIRECTORY");
 	if (directory == NULL) {
@@ -462,9 +465,74 @@ vduse_reconnect_path_init(void)
 	VHOST_CONFIG_LOG("vduse", INFO, "Created VDUSE reconnect directory in %s",
 			vduse_reconnect_dir);
 
+	vduse_reconnect_path_set = true;
+
 	return 0;
 }
 
+static int
+vduse_reconnect_log_map(const char *dev_name, struct vhost_reconnect_data **reco_log, bool create)
+{
+	char reco_file[PATH_MAX];
+	int fd, ret;
+
+	if (vduse_reconnect_path_init() < 0) {
+		VHOST_CONFIG_LOG(dev_name, ERR, "Failed to initialize reconnect path");
+		return -1;
+	}
+
+	ret = snprintf(reco_file, sizeof(reco_file), "%s/%s", vduse_reconnect_dir, dev_name);
+	if (ret < 0 || ret == sizeof(reco_file)) {
+		VHOST_CONFIG_LOG(dev_name, ERR, "Failed to create vduse reconnect path name");
+		return -1;
+	}
+
+	if (create) {
+		fd = open(reco_file, O_CREAT | O_EXCL | O_RDWR, 0600);
+		if (fd < 0) {
+			if (errno == EEXIST) {
+				VHOST_CONFIG_LOG(dev_name, ERR, "Reconnect file %s exists but not the device",
+						reco_file);
+			} else {
+				VHOST_CONFIG_LOG(dev_name, ERR, "Failed to open reconnect file %s (%s)",
+						reco_file, strerror(errno));
+			}
+			return -1;
+		}
+
+		ret = ftruncate(fd, sizeof(**reco_log));
+		if (ret < 0) {
+			VHOST_CONFIG_LOG(dev_name, ERR, "Failed to truncate reconnect file %s (%s)",
+					reco_file, strerror(errno));
+			goto out_close;
+		}
+	} else {
+		fd = open(reco_file, O_RDWR, 0600);
+		if (fd < 0) {
+			if (errno == ENOENT)
+				VHOST_CONFIG_LOG(dev_name, ERR, "Missing reconnect file (%s)", reco_file);
+			else
+				VHOST_CONFIG_LOG(dev_name, ERR, "Failed to open reconnect file %s (%s)",
+						reco_file, strerror(errno));
+			return -1;
+		}
+	}
+
+	*reco_log = mmap(NULL, sizeof(**reco_log), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+	if (*reco_log == MAP_FAILED) {
+		VHOST_CONFIG_LOG(dev_name, ERR, "Failed to mmap reconnect file %s (%s)",
+				reco_file, strerror(errno));
+		ret = -1;
+		goto out_close;
+	}
+	ret = 0;
+
+out_close:
+	close(fd);
+
+	return ret;
+}
+
 static void
 vduse_reconnect_handler(int fd, void *arg, int *remove)
 {
@@ -519,14 +587,13 @@ vduse_reconnect_start_device(struct virtio_net *dev)
 int
 vduse_device_create(const char *path, bool compliant_ol_flags)
 {
-	int control_fd, dev_fd, vid, ret, reco_fd;
+	int control_fd, dev_fd, vid, ret;
 	uint32_t i, max_queue_pairs, total_queues;
 	struct virtio_net *dev;
 	struct virtio_net_config vnet_config = {{ 0 }};
 	uint64_t ver = VHOST_VDUSE_API_VERSION;
 	uint64_t features;
 	const char *name = path + strlen("/dev/vduse/");
-	char reconnect_file[PATH_MAX];
 	struct vhost_reconnect_data *reconnect_log = MAP_FAILED;
 	bool reconnect = false;
 
@@ -538,20 +605,6 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 		}
 	}
 
-	if (vduse_reconnect_path_set == false) {
-		if (vduse_reconnect_path_init() < 0) {
-			VHOST_CONFIG_LOG(path, ERR, "failed to initialize reconnect path");
-			return -1;
-		}
-		vduse_reconnect_path_set = true;
-	}
-
-	ret = snprintf(reconnect_file, sizeof(reconnect_file), "%s/%s", vduse_reconnect_dir, name);
-	if (ret < 0 || ret == sizeof(reconnect_file)) {
-		VHOST_CONFIG_LOG(name, ERR, "Failed to create vduse reconnect path name");
-		return -1;
-	}
-
 	control_fd = open(VDUSE_CTRL_PATH, O_RDWR);
 	if (control_fd < 0) {
 		VHOST_CONFIG_LOG(name, ERR, "Failed to open %s: %s",
@@ -591,27 +644,9 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 		VHOST_CONFIG_LOG(name, INFO, "Device already exists, reconnecting...");
 		reconnect = true;
 
-		reco_fd = open(reconnect_file, O_RDWR, 0600);
-		if (reco_fd < 0) {
-			if (errno == ENOENT)
-				VHOST_CONFIG_LOG(name, ERR, "Missing reconnect file (%s)",
-						reconnect_file);
-			else
-				VHOST_CONFIG_LOG(name, ERR, "Failed to open reconnect file %s (%s)",
-						reconnect_file, strerror(errno));
-			ret = -1;
-			goto out_dev_close;
-		}
-
-		reconnect_log = mmap(NULL, sizeof(*reconnect_log), PROT_READ | PROT_WRITE,
-				MAP_SHARED, reco_fd, 0);
-		close(reco_fd);
-		if (reconnect_log == MAP_FAILED) {
-			VHOST_CONFIG_LOG(name, ERR, "Failed to mmap reconnect file %s (%s)",
-					reconnect_file, strerror(errno));
-			ret = -1;
+		ret = vduse_reconnect_log_map(name, &reconnect_log, false);
+		if (ret < 0)
 			goto out_dev_close;
-		}
 
 		if (reconnect_log->version != VHOST_RECONNECT_VERSION) {
 			VHOST_CONFIG_LOG(name, ERR,
@@ -637,36 +672,9 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 	} else if (errno == ENOENT) {
 		struct vduse_dev_config *dev_config;
 
-		reco_fd = open(reconnect_file, O_CREAT | O_EXCL | O_RDWR, 0600);
-		if (reco_fd < 0) {
-			if (errno == EEXIST) {
-				VHOST_CONFIG_LOG(name, ERR, "Reconnect file %s exists but not the device",
-						reconnect_file);
-			} else {
-				VHOST_CONFIG_LOG(name, ERR, "Failed to open reconnect file %s (%s)",
-						reconnect_file, strerror(errno));
-			}
-			ret = -1;
-			goto out_ctrl_close;
-		}
-
-		ret = ftruncate(reco_fd, sizeof(*reconnect_log));
-		if (ret < 0) {
-			VHOST_CONFIG_LOG(name, ERR, "Failed to truncate reconnect file %s (%s)",
-					reconnect_file, strerror(errno));
-			close(reco_fd);
-			goto out_ctrl_close;
-		}
-
-		reconnect_log = mmap(NULL, sizeof(*reconnect_log), PROT_READ | PROT_WRITE,
-					MAP_SHARED, reco_fd, 0);
-		close(reco_fd);
-		if (reconnect_log == MAP_FAILED) {
-			VHOST_CONFIG_LOG(name, ERR, "Failed to mmap reconnect file %s (%s)",
-					reconnect_file, strerror(errno));
-			ret = -1;
+		ret = vduse_reconnect_log_map(name, &reconnect_log, true);
+		if (ret < 0)
 			goto out_ctrl_close;
-		}
 
 		reconnect_log->version = VHOST_RECONNECT_VERSION;
 
-- 
2.46.2

[PATCH v3 5/6] vhost: fix and refactor VDUSE reconnect log check

[Maxime Coquelin]

This patch fixes missing error handling in checking the
reconnect log version, and takes the opportunity to move
all the checks into a dedicated function to simply VDUSE
device creation code.

Fixes: da79cc7fda76 ("vhost: add reconnection support to VDUSE")

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/vduse.c | 51 ++++++++++++++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 20 deletions(-)

diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
index aae20dfc55..c18692f834 100644
--- a/lib/vhost/vduse.c
+++ b/lib/vhost/vduse.c
@@ -533,6 +533,35 @@ vduse_reconnect_log_map(const char *dev_name, struct vhost_reconnect_data **reco
 	return ret;
 }
 
+static int
+vduse_reconnect_log_check(struct vhost_reconnect_data *reco_log,
+			  const char *dev_name,
+			  uint64_t features, uint32_t total_queues)
+{
+	if (reco_log->version != VHOST_RECONNECT_VERSION) {
+		VHOST_CONFIG_LOG(dev_name, ERR,
+				"Version mismatch between backend (0x%x) & reconnection file (0x%x)",
+				VHOST_RECONNECT_VERSION, reco_log->version);
+		return -1;
+	}
+
+	if ((reco_log->features & features) != reco_log->features) {
+		VHOST_CONFIG_LOG(dev_name, ERR,
+				"Features mismatch between backend (0x%" PRIx64 ") & reconnection file (0x%" PRIx64 ")",
+				features, reco_log->features);
+		return -1;
+	}
+
+	if (reco_log->nr_vrings != total_queues) {
+		VHOST_CONFIG_LOG(dev_name, ERR,
+				"Queues number mismatch between backend (%u) and reconnection file (%u)",
+				total_queues, reco_log->nr_vrings);
+		return -1;
+	}
+
+	return 0;
+}
+
 static void
 vduse_reconnect_handler(int fd, void *arg, int *remove)
 {
@@ -648,27 +677,9 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 		if (ret < 0)
 			goto out_dev_close;
 
-		if (reconnect_log->version != VHOST_RECONNECT_VERSION) {
-			VHOST_CONFIG_LOG(name, ERR,
-					"Version mismatch between backend (0x%x) & reconnection file (0x%x)",
-					VHOST_RECONNECT_VERSION, reconnect_log->version);
-		}
-
-		if ((reconnect_log->features & features) != reconnect_log->features) {
-			VHOST_CONFIG_LOG(name, ERR,
-					"Features mismatch between backend (0x%" PRIx64 ") & reconnection file (0x%" PRIx64 ")",
-					features, reconnect_log->features);
-			ret = -1;
-			goto out_log_unmap;
-		}
-
-		if (reconnect_log->nr_vrings != total_queues) {
-			VHOST_CONFIG_LOG(name, ERR,
-					"Queues number mismatch between backend (%u) and reconnection file (%u)",
-					total_queues, reconnect_log->nr_vrings);
-			ret = -1;
+		ret = vduse_reconnect_log_check(reconnect_log, name, features, total_queues);
+		if (ret < 0)
 			goto out_log_unmap;
-		}
 	} else if (errno == ENOENT) {
 		struct vduse_dev_config *dev_config;
 
-- 
2.46.2

[PATCH v3 6/6] vhost: move VDUSE reconnection after device is created

[Maxime Coquelin]

This patch moves the VDUSE reconnection log mapping and
setup after the Vhost device is created in order to
simplify the device creation and its error path.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/vduse.c | 111 ++++++++++++++++++++++------------------------
 1 file changed, 52 insertions(+), 59 deletions(-)

diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
index c18692f834..8ba58555f9 100644
--- a/lib/vhost/vduse.c
+++ b/lib/vhost/vduse.c
@@ -471,19 +471,20 @@ vduse_reconnect_path_init(void)
 }
 
 static int
-vduse_reconnect_log_map(const char *dev_name, struct vhost_reconnect_data **reco_log, bool create)
+vduse_reconnect_log_map(struct virtio_net *dev, bool create)
 {
 	char reco_file[PATH_MAX];
 	int fd, ret;
+	const char *name = dev->ifname + strlen("/dev/vduse/");
 
 	if (vduse_reconnect_path_init() < 0) {
-		VHOST_CONFIG_LOG(dev_name, ERR, "Failed to initialize reconnect path");
+		VHOST_CONFIG_LOG(dev->ifname, ERR, "Failed to initialize reconnect path");
 		return -1;
 	}
 
-	ret = snprintf(reco_file, sizeof(reco_file), "%s/%s", vduse_reconnect_dir, dev_name);
+	ret = snprintf(reco_file, sizeof(reco_file), "%s/%s", vduse_reconnect_dir, name);
 	if (ret < 0 || ret == sizeof(reco_file)) {
-		VHOST_CONFIG_LOG(dev_name, ERR, "Failed to create vduse reconnect path name");
+		VHOST_CONFIG_LOG(dev->ifname, ERR, "Failed to create vduse reconnect path name");
 		return -1;
 	}
 
@@ -491,18 +492,18 @@ vduse_reconnect_log_map(const char *dev_name, struct vhost_reconnect_data **reco
 		fd = open(reco_file, O_CREAT | O_EXCL | O_RDWR, 0600);
 		if (fd < 0) {
 			if (errno == EEXIST) {
-				VHOST_CONFIG_LOG(dev_name, ERR, "Reconnect file %s exists but not the device",
+				VHOST_CONFIG_LOG(dev->ifname, ERR, "Reconnect file %s exists but not the device",
 						reco_file);
 			} else {
-				VHOST_CONFIG_LOG(dev_name, ERR, "Failed to open reconnect file %s (%s)",
+				VHOST_CONFIG_LOG(dev->ifname, ERR, "Failed to open reconnect file %s (%s)",
 						reco_file, strerror(errno));
 			}
 			return -1;
 		}
 
-		ret = ftruncate(fd, sizeof(**reco_log));
+		ret = ftruncate(fd, sizeof(*dev->reconnect_log));
 		if (ret < 0) {
-			VHOST_CONFIG_LOG(dev_name, ERR, "Failed to truncate reconnect file %s (%s)",
+			VHOST_CONFIG_LOG(dev->ifname, ERR, "Failed to truncate reconnect file %s (%s)",
 					reco_file, strerror(errno));
 			goto out_close;
 		}
@@ -510,17 +511,18 @@ vduse_reconnect_log_map(const char *dev_name, struct vhost_reconnect_data **reco
 		fd = open(reco_file, O_RDWR, 0600);
 		if (fd < 0) {
 			if (errno == ENOENT)
-				VHOST_CONFIG_LOG(dev_name, ERR, "Missing reconnect file (%s)", reco_file);
+				VHOST_CONFIG_LOG(dev->ifname, ERR, "Missing reconnect file (%s)", reco_file);
 			else
-				VHOST_CONFIG_LOG(dev_name, ERR, "Failed to open reconnect file %s (%s)",
+				VHOST_CONFIG_LOG(dev->ifname, ERR, "Failed to open reconnect file %s (%s)",
 						reco_file, strerror(errno));
 			return -1;
 		}
 	}
 
-	*reco_log = mmap(NULL, sizeof(**reco_log), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
-	if (*reco_log == MAP_FAILED) {
-		VHOST_CONFIG_LOG(dev_name, ERR, "Failed to mmap reconnect file %s (%s)",
+	dev->reconnect_log = mmap(NULL, sizeof(*dev->reconnect_log), PROT_READ | PROT_WRITE,
+				MAP_SHARED, fd, 0);
+	if (dev->reconnect_log == MAP_FAILED) {
+		VHOST_CONFIG_LOG(dev->ifname, ERR, "Failed to mmap reconnect file %s (%s)",
 				reco_file, strerror(errno));
 		ret = -1;
 		goto out_close;
@@ -534,28 +536,26 @@ vduse_reconnect_log_map(const char *dev_name, struct vhost_reconnect_data **reco
 }
 
 static int
-vduse_reconnect_log_check(struct vhost_reconnect_data *reco_log,
-			  const char *dev_name,
-			  uint64_t features, uint32_t total_queues)
+vduse_reconnect_log_check(struct virtio_net *dev, uint64_t features, uint32_t total_queues)
 {
-	if (reco_log->version != VHOST_RECONNECT_VERSION) {
-		VHOST_CONFIG_LOG(dev_name, ERR,
+	if (dev->reconnect_log->version != VHOST_RECONNECT_VERSION) {
+		VHOST_CONFIG_LOG(dev->ifname, ERR,
 				"Version mismatch between backend (0x%x) & reconnection file (0x%x)",
-				VHOST_RECONNECT_VERSION, reco_log->version);
+				VHOST_RECONNECT_VERSION, dev->reconnect_log->version);
 		return -1;
 	}
 
-	if ((reco_log->features & features) != reco_log->features) {
-		VHOST_CONFIG_LOG(dev_name, ERR,
+	if ((dev->reconnect_log->features & features) != dev->reconnect_log->features) {
+		VHOST_CONFIG_LOG(dev->ifname, ERR,
 				"Features mismatch between backend (0x%" PRIx64 ") & reconnection file (0x%" PRIx64 ")",
-				features, reco_log->features);
+				features, dev->reconnect_log->features);
 		return -1;
 	}
 
-	if (reco_log->nr_vrings != total_queues) {
-		VHOST_CONFIG_LOG(dev_name, ERR,
+	if (dev->reconnect_log->nr_vrings != total_queues) {
+		VHOST_CONFIG_LOG(dev->ifname, ERR,
 				"Queues number mismatch between backend (%u) and reconnection file (%u)",
-				total_queues, reco_log->nr_vrings);
+				total_queues, dev->reconnect_log->nr_vrings);
 		return -1;
 	}
 
@@ -623,7 +623,6 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 	uint64_t ver = VHOST_VDUSE_API_VERSION;
 	uint64_t features;
 	const char *name = path + strlen("/dev/vduse/");
-	struct vhost_reconnect_data *reconnect_log = MAP_FAILED;
 	bool reconnect = false;
 
 	if (vduse.fdset == NULL) {
@@ -672,29 +671,15 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 	if (dev_fd >= 0) {
 		VHOST_CONFIG_LOG(name, INFO, "Device already exists, reconnecting...");
 		reconnect = true;
-
-		ret = vduse_reconnect_log_map(name, &reconnect_log, false);
-		if (ret < 0)
-			goto out_dev_close;
-
-		ret = vduse_reconnect_log_check(reconnect_log, name, features, total_queues);
-		if (ret < 0)
-			goto out_log_unmap;
 	} else if (errno == ENOENT) {
 		struct vduse_dev_config *dev_config;
 
-		ret = vduse_reconnect_log_map(name, &reconnect_log, true);
-		if (ret < 0)
-			goto out_ctrl_close;
-
-		reconnect_log->version = VHOST_RECONNECT_VERSION;
-
 		dev_config = malloc(offsetof(struct vduse_dev_config, config) +
 				sizeof(vnet_config));
 		if (!dev_config) {
 			VHOST_CONFIG_LOG(name, ERR, "Failed to allocate VDUSE config");
 			ret = -1;
-			goto out_log_unmap;
+			goto out_ctrl_close;
 		}
 
 		vnet_config.max_virtqueue_pairs = max_queue_pairs;
@@ -715,18 +700,15 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 		if (ret < 0) {
 			VHOST_CONFIG_LOG(name, ERR, "Failed to create VDUSE device: %s",
 					strerror(errno));
-			goto out_log_unmap;
+			goto out_ctrl_close;
 		}
 
-		memcpy(&reconnect_log->config, &vnet_config, sizeof(vnet_config));
-		reconnect_log->nr_vrings = total_queues;
-
 		dev_fd = open(path, O_RDWR);
 		if (dev_fd < 0) {
 			VHOST_CONFIG_LOG(name, ERR, "Failed to open newly created device %s: %s",
 					path, strerror(errno));
 			ret = -1;
-			goto out_log_unmap;
+			goto out_ctrl_close;
 		}
 	} else {
 		VHOST_CONFIG_LOG(name, ERR, "Failed to open device %s: %s",
@@ -739,14 +721,14 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 	if (ret < 0) {
 		VHOST_CONFIG_LOG(name, ERR, "Failed to set chardev as non-blocking: %s",
 				strerror(errno));
-		goto out_log_unmap;
+		goto out_dev_close;
 	}
 
 	vid = vhost_new_device(&vduse_backend_ops);
 	if (vid < 0) {
 		VHOST_CONFIG_LOG(name, ERR, "Failed to create new Vhost device");
 		ret = -1;
-		goto out_log_unmap;
+		goto out_dev_close;
 	}
 
 	dev = get_device(vid);
@@ -758,10 +740,22 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 	strncpy(dev->ifname, path, IF_NAME_SZ - 1);
 	dev->vduse_ctrl_fd = control_fd;
 	dev->vduse_dev_fd = dev_fd;
-	dev->reconnect_log = reconnect_log;
-	reconnect_log = MAP_FAILED;
-	if (reconnect)
+
+	ret = vduse_reconnect_log_map(dev, !reconnect);
+	if (ret < 0)
+		goto out_dev_destroy;
+
+	if (reconnect) {
+		ret = vduse_reconnect_log_check(dev, features, total_queues);
+		if (ret < 0)
+			goto out_log_unmap;
+
 		dev->status = dev->reconnect_log->status;
+	} else {
+		dev->reconnect_log->version = VHOST_RECONNECT_VERSION;
+		dev->reconnect_log->nr_vrings = total_queues;
+		memcpy(&dev->reconnect_log->config, &vnet_config, sizeof(vnet_config));
+	}
 
 	vhost_setup_virtio_net(dev->vid, true, compliant_ol_flags, true, true);
 
@@ -772,11 +766,11 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 		ret = alloc_vring_queue(dev, i);
 		if (ret) {
 			VHOST_CONFIG_LOG(name, ERR, "Failed to alloc vring %d metadata", i);
-			goto out_dev_destroy;
+			goto out_log_unmap;
 		}
 
 		vq = dev->virtqueue[i];
-		vq->reconnect_log = &reconnect_log->vring[i];
+		vq->reconnect_log = &dev->reconnect_log->vring[i];
 
 		if (reconnect)
 			continue;
@@ -787,7 +781,7 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 		ret = ioctl(dev->vduse_dev_fd, VDUSE_VQ_SETUP, &vq_cfg);
 		if (ret) {
 			VHOST_CONFIG_LOG(name, ERR, "Failed to set-up VQ %d", i);
-			goto out_dev_destroy;
+			goto out_log_unmap;
 		}
 	}
 
@@ -797,22 +791,21 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
 	if (ret) {
 		VHOST_CONFIG_LOG(name, ERR, "Failed to add fd %d to vduse fdset",
 				dev->vduse_dev_fd);
-		goto out_dev_destroy;
+		goto out_log_unmap;
 	}
 
 	if (reconnect && dev->status & VIRTIO_DEVICE_STATUS_DRIVER_OK)  {
 		ret = vduse_reconnect_start_device(dev);
 		if (ret)
-			goto out_dev_destroy;
+			goto out_log_unmap;
 	}
 
 	return 0;
 
+out_log_unmap:
+	munmap(dev->reconnect_log, sizeof(*dev->reconnect_log));
 out_dev_destroy:
 	vhost_destroy_device(vid);
-out_log_unmap:
-	if (reconnect_log != MAP_FAILED)
-		munmap(reconnect_log, sizeof(*reconnect_log));
 out_dev_close:
 	if (dev_fd >= 0)
 		close(dev_fd);
-- 
2.46.2

Re: [PATCH v3 1/6] vhost: fix VDUSE device creation error handling

[David Marchand]

On Thu, Oct 24, 2024 at 11:44 AM Maxime Coquelin
<maxime.coquelin@redhat.com> wrote:
>
> This patch fixes missing reconnection log unmapping
> miss in the error path at VDUSE creation time.
>
> Coverity issue: 445525
> Fixes: da79cc7fda76 ("vhost: add reconnection support to VDUSE")
>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>


-- 
David Marchand

Re: [PATCH v3 3/6] vhost: fix VDUSE reconnect device start failure

[David Marchand]

On Thu, Oct 24, 2024 at 11:44 AM Maxime Coquelin
<maxime.coquelin@redhat.com> wrote:
>
> This patch fixes a FD leak in the VDUSE device reconnect
> code fails to start the device.
>
> Also take the opportunity to refactor the related code into
> a dedicated function.
>
> Fixes: da79cc7fda76 ("vhost: add reconnection support to VDUSE")
>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>


-- 
David Marchand

Re: [PATCH v3 4/6] vhost: refactor VDUSE reconnection log mapping

[David Marchand]

On Thu, Oct 24, 2024 at 11:44 AM Maxime Coquelin
<maxime.coquelin@redhat.com> wrote:
>
> This patch moves the VDUSE reconnection log mapping, as
> well as creation if needed, into a dedicated function.
>
> This is a preliminary rework to simplify VDUSE device
> creation.
>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>


-- 
David Marchand

Re: [PATCH v3 5/6] vhost: fix and refactor VDUSE reconnect log check

[David Marchand]

On Thu, Oct 24, 2024 at 11:44 AM Maxime Coquelin
<maxime.coquelin@redhat.com> wrote:
>
> This patch fixes missing error handling in checking the
> reconnect log version, and takes the opportunity to move
> all the checks into a dedicated function to simply VDUSE
> device creation code.
>
> Fixes: da79cc7fda76 ("vhost: add reconnection support to VDUSE")
>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>


-- 
David Marchand

Re: [PATCH v3 6/6] vhost: move VDUSE reconnection after device is created

[David Marchand]

On Thu, Oct 24, 2024 at 11:44 AM Maxime Coquelin
<maxime.coquelin@redhat.com> wrote:
>
> This patch moves the VDUSE reconnection log mapping and
> setup after the Vhost device is created in order to
> simplify the device creation and its error path.
>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>


-- 
David Marchand

Re: [PATCH v3 0/6] VDUSE reconnection fixes and cleanup

[Maxime Coquelin]

On 10/24/24 11:44, Maxime Coquelin wrote:
> This series provides various fixes for VDUSE reconnection
> introduced in -rc1, some of them being reported by
> Coverity.
> 
> The series also takes the opportunity to refactor
> reconnection to make it more self-contained to simplify
> readability and error path handling.
> 
> Changes in v2:
> ==============
> - Avoid superluous error logging (David)
> - VDUSE in capital letter in commit title 1 (David)
> - Declare dev_config in the code block it is used (David)
> - Fix wrong goto in intermediate patch (Maxime)
> 
> Maxime Coquelin (6):
>    vhost: fix VDUSE device creation error handling
>    vhost: fix possible TOCTOU in VDUSE dev creation
>    vhost: fix VDUSE reconnect device start failure
>    vhost: refactor VDUSE reconnection log mapping
>    vhost: fix and refactor VDUSE reconnect log check
>    vhost: move VDUSE reconnection after device is created
> 
>   lib/vhost/vduse.c | 322 ++++++++++++++++++++++++++--------------------
>   1 file changed, 181 insertions(+), 141 deletions(-)
> 

Applied to next-virtio/for-next-net

Thanks,
Maxime