imsm: add generic method to resolve "device" links

Each virtual device is linked with parent by "device". This patch adds
possibility to get previous device in sysfs tree.

Depending on device type, there is a different amount of virutal
layers. The best we can do is allow to directly specify how many
"device" links need to be resolved. This approach also allows to get
previous virtual device, which may contain some attributes.

Simplify fd2devname, this function doesn't require new functionality and
shall use generic fd2kname.

For nvme drives represented via nvme-subystem when path to block
device if requested, then return it without translation.

Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

1 files changed, 24 insertions, 39 deletions

diff --git a/super-intel.c b/super-intel.c
index 54699129..cff8550b 100644
--- a/super-intel.c
+++ b/super-intel.c
@@ -694,7 +694,7 @@ static struct sys_dev* find_disk_attached_hba(int fd, const char *devname)
 	if (fd < 0)
 		disk_path  = (char *) devname;
 	else
-		disk_path = diskfd_to_devpath(fd);
+		disk_path = diskfd_to_devpath(fd, 1, NULL);
 
 	if (!disk_path)
 		return 0;
@@ -2253,7 +2253,7 @@ static int ahci_enumerate_ports(const char *hba_path, int port_count, int host_b
 
 		if (sscanf(ent->d_name, "%d:%d", &major, &minor) != 2)
 			continue;
-		path = devt_to_devpath(makedev(major, minor));
+		path = devt_to_devpath(makedev(major, minor), 1, NULL);
 		if (!path)
 			continue;
 		if (!path_attached_to_hba(path, hba_path)) {
@@ -2407,7 +2407,7 @@ static int print_nvme_info(struct sys_dev *hba)
 				continue;
 			}
 
-			device_path = diskfd_to_devpath(fd);
+			device_path = diskfd_to_devpath(fd, 1, NULL);
 			if (!device_path) {
 				close(fd);
 				continue;
@@ -4015,28 +4015,13 @@ static int compare_super_imsm(struct supertype *st, struct supertype *tst,
 
 static void fd2devname(int fd, char *name)
 {
-	struct stat st;
-	char path[256];
-	char dname[PATH_MAX];
 	char *nm;
-	int rv;
-
-	name[0] = '\0';
-	if (fstat(fd, &st) != 0)
-		return;
-	sprintf(path, "/sys/dev/block/%d:%d",
-		major(st.st_rdev), minor(st.st_rdev));
 
-	rv = readlink(path, dname, sizeof(dname)-1);
-	if (rv <= 0)
+	nm = fd2kname(fd);
+	if (!nm)
 		return;
 
-	dname[rv] = '\0';
-	nm = strrchr(dname, '/');
-	if (nm) {
-		nm++;
-		snprintf(name, MAX_RAID_SERIAL_LEN, "/dev/%s", nm);
-	}
+	snprintf(name, MAX_RAID_SERIAL_LEN, "/dev/%s", nm);
 }
 
 static int nvme_get_serial(int fd, void *buf, size_t buf_len)
@@ -5941,29 +5926,23 @@ static int add_to_super_imsm(struct supertype *st, mdu_disk_info_t *dk,
 		free(dd);
 		abort();
 	}
+
 	if (super->hba && ((super->hba->type == SYS_DEV_NVME) ||
 	   (super->hba->type == SYS_DEV_VMD))) {
 		int i;
-		char *devpath = diskfd_to_devpath(fd);
-		char controller_path[PATH_MAX];
-		char *controller_name;
+		char cntrl_path[PATH_MAX];
+		char *cntrl_name;
+		char pci_dev_path[PATH_MAX];
 
-		if (!devpath) {
-			pr_err("failed to get devpath, aborting\n");
+		if (!diskfd_to_devpath(fd, 2, pci_dev_path) ||
+		    !diskfd_to_devpath(fd, 1, cntrl_path)) {
+			pr_err("failed to get dev_path, aborting\n");
 			if (dd->devname)
 				free(dd->devname);
 			free(dd);
 			return 1;
 		}
 
-		snprintf(controller_path, PATH_MAX-1, "%s/device", devpath);
-
-		controller_name = basename(devpath);
-		if (is_multipath_nvme(fd))
-			pr_err("%s controller supports Multi-Path I/O, Intel (R) VROC does not support multipathing\n", controller_name);
-
-		free(devpath);
-
 		if (!imsm_is_nvme_supported(dd->fd, 1)) {
 			if (dd->devname)
 				free(dd->devname);
@@ -5971,7 +5950,12 @@ static int add_to_super_imsm(struct supertype *st, mdu_disk_info_t *dk,
 			return 1;
 		}
 
-		if (devpath_to_vendor(controller_path) == 0x8086) {
+		cntrl_name = basename(cntrl_path);
+		if (is_multipath_nvme(fd))
+			pr_err("%s controller supports Multi-Path I/O, Intel (R) VROC does not support multipathing\n",
+			       cntrl_name);
+
+		if (devpath_to_vendor(pci_dev_path) == 0x8086) {
 			/*
 			 * If Intel's NVMe drive has serial ended with
 			 * "-A","-B","-1" or "-2" it means that this is "x8"
@@ -6985,7 +6969,7 @@ get_devices(const char *hba_path)
 		char *path = NULL;
 		if (sscanf(ent->d_name, "%d:%d", &major, &minor) != 2)
 			continue;
-		path = devt_to_devpath(makedev(major, minor));
+		path = devt_to_devpath(makedev(major, minor), 1, NULL);
 		if (!path)
 			continue;
 		if (!path_attached_to_hba(path, hba_path)) {
@@ -10648,7 +10632,7 @@ int validate_container_imsm(struct mdinfo *info)
 	struct sys_dev *hba = NULL;
 	struct sys_dev *intel_devices = find_intel_devices();
 	char *dev_path = devt_to_devpath(makedev(info->disk.major,
-									info->disk.minor));
+						 info->disk.minor), 1, NULL);
 
 	for (idev = intel_devices; idev; idev = idev->next) {
 		if (dev_path && strstr(dev_path, idev->path)) {
@@ -10669,7 +10653,8 @@ int validate_container_imsm(struct mdinfo *info)
 	struct mdinfo *dev;
 
 	for (dev = info->next; dev; dev = dev->next) {
-		dev_path = devt_to_devpath(makedev(dev->disk.major, dev->disk.minor));
+		dev_path = devt_to_devpath(makedev(dev->disk.major,
+						   dev->disk.minor), 1, NULL);
 
 		struct sys_dev *hba2 = NULL;
 		for (idev = intel_devices; idev; idev = idev->next) {
@@ -11181,7 +11166,7 @@ static const char *imsm_get_disk_controller_domain(const char *path)
 		struct sys_dev* hba;
 		char *path;
 
-		path = devt_to_devpath(st.st_rdev);
+		path = devt_to_devpath(st.st_rdev, 1, NULL);
 		if (path == NULL)
 			return "unknown";
 		hba = find_disk_attached_hba(-1, path);