mdadm/util: unify stat checking blkdev into function

declare function stat_is_blkdev() to integrate repeated stat
checking blkdev operations, it returns 'true/1' when it is a
block device, and returns 'false/0' when it isn't.
The devname is necessary parameter, *rdev is optional, parse
the pointer of dev_t *rdev, if valid, assigned device number
to dev_t *rdev, if NULL, ignores.

Signed-off-by: Zhilong Liu <zlliu@suse.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

Assemble.c

@@ -512,15 +512,12 @@ static int select_devices(struct mddev_dev *devlist,
 
 	/* Now reject spares that don't match domains of identified members */
 	for (tmpdev = devlist; tmpdev; tmpdev = tmpdev->next) {
-		struct stat stb;
 		if (tmpdev->used != 3)
 			continue;
-		if (stat(tmpdev->devname, &stb)< 0) {
-			pr_err("fstat failed for %s: %s\n",
-			       tmpdev->devname, strerror(errno));
+		if (!stat_is_blkdev(tmpdev->devname, &rdev)) {
 			tmpdev->used = 2;
 		} else {
-			struct dev_policy *pol = devid_policy(stb.st_rdev);
+			struct dev_policy *pol = devid_policy(rdev);
 			int dt = domain_test(domains, pol, NULL);
 			if (inargv && dt != 0)
 				/* take this spare as domains match

Build.c

@@ -41,7 +41,6 @@ int Build(char *mddev, struct mddev_dev *devlist,
 	 * cc = chunk size factor: 0==4k, 1==8k etc.
 	 */
 	int i;
-	struct stat stb;
 	dev_t rdev;
 	int subdevs = 0, missing_disks = 0;
 	struct mddev_dev *dv;
@@ -65,16 +64,8 @@ int Build(char *mddev, struct mddev_dev *devlist,
 			missing_disks++;
 			continue;
 		}
-		if (stat(dv->devname, &stb)) {
-			pr_err("Cannot find %s: %s\n",
-				dv->devname, strerror(errno));
+		if (!stat_is_blkdev(dv->devname, NULL))
 			return 1;
-		}
-		if ((stb.st_mode & S_IFMT) != S_IFBLK) {
-			pr_err("%s is not a block device.\n",
-				dv->devname);
-			return 1;
-		}
 	}
 
 	if (s->raiddisks != subdevs) {
@@ -162,16 +153,8 @@ int Build(char *mddev, struct mddev_dev *devlist,
 
 		if (strcmp("missing", dv->devname) == 0)
 			continue;
-		if (stat(dv->devname, &stb)) {
-			pr_err("Weird: %s has disappeared.\n",
-				dv->devname);
+		if (!stat_is_blkdev(dv->devname, &rdev))
 			goto abort;
-		}
-		if ((stb.st_mode & S_IFMT)!= S_IFBLK) {
-			pr_err("Weird: %s is no longer a block device.\n",
-				dv->devname);
-			goto abort;
-		}
 		fd = open(dv->devname, O_RDONLY|O_EXCL);
 		if (fd < 0) {
 			pr_err("Cannot open %s: %s\n",
@@ -187,8 +170,8 @@ int Build(char *mddev, struct mddev_dev *devlist,
 		disk.state = (1<<MD_DISK_SYNC) | (1<<MD_DISK_ACTIVE);
 		if (dv->writemostly == FlagSet)
 			disk.state |= 1<<MD_DISK_WRITEMOSTLY;
-		disk.major = major(stb.st_rdev);
-		disk.minor = minor(stb.st_rdev);
+		disk.major = major(rdev);
+		disk.minor = minor(rdev);
 		if (ioctl(mdfd, ADD_NEW_DISK, &disk)) {
 			pr_err("ADD_NEW_DISK failed for %s: %s\n",
 			       dv->devname, strerror(errno));

Incremental.c

@@ -86,8 +86,7 @@ int Incremental(struct mddev_dev *devlist, struct context *c,
 	 * - if number of OK devices match expected, or -R and there are enough,
 	 *   start the array (auto-readonly).
 	 */
-	struct stat stb;
-	dev_t rdev;
+	dev_t rdev, rdev2;
 	struct mdinfo info, dinfo;
 	struct mdinfo *sra = NULL, *d;
 	struct mddev_ident *match;
@@ -108,18 +107,8 @@ int Incremental(struct mddev_dev *devlist, struct context *c,
 
 	struct createinfo *ci = conf_get_create_info();
 
-	if (stat(devname, &stb) < 0) {
-		if (c->verbose >= 0)
-			pr_err("stat failed for %s: %s.\n",
-				devname, strerror(errno));
+	if (!stat_is_blkdev(devname, &rdev))
 		return rv;
-	}
-	if ((stb.st_mode & S_IFMT) != S_IFBLK) {
-		if (c->verbose >= 0)
-			pr_err("%s is not a block device.\n",
-				devname);
-		return rv;
-	}
 	dfd = dev_open(devname, O_RDONLY);
 	if (dfd < 0) {
 		if (c->verbose >= 0)
@@ -158,10 +147,8 @@ int Incremental(struct mddev_dev *devlist, struct context *c,
 	if (!devlist) {
 		devlist = conf_get_devs();
 		for (;devlist; devlist = devlist->next) {
-			struct stat st2;
-			if (stat(devlist->devname, &st2) == 0 &&
-			    (st2.st_mode & S_IFMT) == S_IFBLK &&
-			    st2.st_rdev == stb.st_rdev)
+			if (stat_is_blkdev(devlist->devname, &rdev2) &&
+			    rdev2 == rdev)
 				break;
 		}
 	}

Manage.c

@@ -1510,24 +1510,16 @@ int Manage_subdevs(char *devname, int fd,
 			 */
 			rdev = makedev(mj, mn);
 		} else {
-			struct stat stb;
 			tfd = dev_open(dv->devname, O_RDONLY);
 			if (tfd >= 0) {
 				fstat_is_blkdev(tfd, dv->devname, &rdev);
 				close(tfd);
 			} else {
 				int open_err = errno;
-				if (stat(dv->devname, &stb) != 0) {
-					pr_err("Cannot find %s: %s\n",
-					       dv->devname, strerror(errno));
-					goto abort;
-				}
-				if ((stb.st_mode & S_IFMT) != S_IFBLK) {
+				if (!stat_is_blkdev(dv->devname, &rdev)) {
 					if (dv->disposition == 'M')
 						/* non-fatal. Also improbable */
 						continue;
-					pr_err("%s is not a block device.\n",
-					       dv->devname);
 					goto abort;
 				}
 				if (dv->disposition == 'r')
@@ -1544,7 +1536,6 @@ int Manage_subdevs(char *devname, int fd,
 					goto abort;
 				}
 			}
-			rdev = stb.st_rdev;
 		}
 		switch(dv->disposition){
 		default:

Monitor.c

@@ -993,23 +993,13 @@ static void link_containers_with_subarrays(struct state *list)
 /* Not really Monitor but ... */
 int Wait(char *dev)
 {
-	struct stat stb;
 	char devnm[32];
-	char *tmp;
 	int rv = 1;
 	int frozen_remaining = 3;
 
-	if (stat(dev, &stb) != 0) {
-		pr_err("Cannot find %s: %s\n", dev,
-			strerror(errno));
+	if (!stat_is_blkdev(dev, NULL))
 		return 2;
-	}
-	tmp = stat2devnm(&stb);
-	if (!tmp) {
-		pr_err("%s is not a block device.\n", dev);
-		return 2;
-	}
-	strcpy(devnm, tmp);
+	strcpy(devnm, dev);
 
 	while(1) {
 		struct mdstat_ent *ms = mdstat_read(1, 0);
@@ -1068,6 +1058,8 @@ int WaitClean(char *dev, int sock, int verbose)
 	int rv = 1;
 	char devnm[32];
 
+	if (!stat_is_blkdev(dev, NULL))
+		return 2;
 	fd = open(dev, O_RDONLY);
 	if (fd < 0) {
 		if (verbose)

mdadm.h

@@ -1435,6 +1435,7 @@ extern int check_partitions(int fd, char *dname,
 			    unsigned long long freesize,
 			    unsigned long long size);
 extern int fstat_is_blkdev(int fd, char *devname, dev_t *rdev);
+extern int stat_is_blkdev(char *devname, dev_t *rdev);
 
 extern int get_mdp_major(void);
 extern int get_maj_min(char *dev, int *major, int *minor);

super-ddf.c

@@ -3490,7 +3490,7 @@ static int validate_geometry_ddf_bvd(struct supertype *st,
 				     char *dev, unsigned long long *freesize,
 				     int verbose)
 {
-	struct stat stb;
+	dev_t rdev;
 	struct ddf_super *ddf = st->sb;
 	struct dl *dl;
 	unsigned long long maxsize;
@@ -3526,13 +3526,11 @@ static int validate_geometry_ddf_bvd(struct supertype *st,
 		return 1;
 	}
 	/* This device must be a member of the set */
-	if (stat(dev, &stb) < 0)
-		return 0;
-	if ((S_IFMT & stb.st_mode) != S_IFBLK)
+	if (!stat_is_blkdev(dev, NULL))
 		return 0;
 	for (dl = ddf->dlist ; dl ; dl = dl->next) {
-		if (dl->major == (int)major(stb.st_rdev) &&
-		    dl->minor == (int)minor(stb.st_rdev))
+		if (dl->major == (int)major(rdev) &&
+		    dl->minor == (int)minor(rdev))
 			break;
 	}
 	if (!dl) {

super-intel.c

@@ -6855,7 +6855,7 @@ static int validate_geometry_imsm_volume(struct supertype *st, int level,
 					 unsigned long long *freesize,
 					 int verbose)
 {
-	struct stat stb;
+	dev_t rdev;
 	struct intel_super *super = st->sb;
 	struct imsm_super *mpb;
 	struct dl *dl;
@@ -6920,13 +6920,11 @@ static int validate_geometry_imsm_volume(struct supertype *st, int level,
 	}
 
 	/* This device must be a member of the set */
-	if (stat(dev, &stb) < 0)
-		return 0;
-	if ((S_IFMT & stb.st_mode) != S_IFBLK)
+	if (!stat_is_blkdev(dev, &rdev))
 		return 0;
 	for (dl = super->disks ; dl ; dl = dl->next) {
-		if (dl->major == (int)major(stb.st_rdev) &&
-		    dl->minor == (int)minor(stb.st_rdev))
+		if (dl->major == (int)major(rdev) &&
+		    dl->minor == (int)minor(rdev))
 			break;
 	}
 	if (!dl) {

util.c

@@ -747,6 +747,23 @@ int fstat_is_blkdev(int fd, char *devname, dev_t *rdev)
 	return 1;
 }
 
+int stat_is_blkdev(char *devname, dev_t *rdev)
+{
+	struct stat stb;
+
+	if (stat(devname, &stb) != 0) {
+		pr_err("stat failed for %s: %s\n", devname, strerror(errno));
+		return 0;
+	}
+	if ((S_IFMT & stb.st_mode) != S_IFBLK) {
+		pr_err("%s is not a block device.\n", devname);
+		return 0;
+	}
+	if (rdev)
+		*rdev = stb.st_rdev;
+	return 1;
+}
+
 int ask(char *mesg)
 {
 	char *add = "";