Hunt for a disk to operate on, if we're passed a partition mountpoint, etc.

Concept reviewed by:	phk

2 files changed, 41 insertions, 2 deletions

diff --git a/lib/libufs/libufs.h b/lib/libufs/libufs.h
index c2f11a9..266f787 100644
--- a/lib/libufs/libufs.h
+++ b/lib/libufs/libufs.h
@@ -80,6 +80,7 @@ struct uufsd {
 				/* superblock as buffer */
 	} d_sbunion;
 	const char *d_error;	/* human readable disk error */
+	int d_mine;		/* internal flags */
 #define	d_fs	d_sbunion.d_fs
 #define	d_sb	d_sbunion.d_sb
 };
diff --git a/lib/libufs/type.c b/lib/libufs/type.c
index 622cba8..d3182d3 100644
--- a/lib/libufs/type.c
+++ b/lib/libufs/type.c
@@ -39,6 +39,8 @@ __FBSDID("$FreeBSD$");
 
 #include <errno.h>
 #include <fcntl.h>
+#include <fstab.h>
+#include <paths.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -46,6 +48,9 @@ __FBSDID("$FreeBSD$");
 
 #include <libufs.h>
 
+/* Internally, track the 'name' value, it's ours. */
+#define	MINE_NAME	0x01
+
 struct uufsd *
 ufs_disk_ctor(const char *name)
 {
@@ -96,19 +101,42 @@ ufs_disk_close(struct uufsd *disk)
 		free(disk->d_inoblock);
 		disk->d_inoblock = NULL;
 	}
+	if (disk->d_mine & MINE_NAME) {
+		free((char *)(uintptr_t)disk->d_name);
+		disk->d_name = NULL;
+	}
 	return 0;
 }
 
 int
 ufs_disk_fillout(struct uufsd *disk, const char *name)
 {
+	struct stat st;
+	struct fstab *fs;
+	const char *oname;
+	char dev[MAXPATHLEN];
 	int fd;
 
 	ERROR(disk, NULL);
 
+	oname = name;
+	fs = getfsfile(name);
+	if (fs != NULL)
+		name = fs->fs_spec;
+again:	if (stat(name, &st) < 0) {
+		if (*name != '/') {
+			if (*name == 'r')
+				name++;
+			snprintf(dev, sizeof(dev), "%s%s", _PATH_DEV, name);
+			name = dev;
+			goto again;
+		}
+		ERROR(disk, "could not find special device");
+		return -1;
+	}
 	fd = open(name, O_RDONLY);
 	if (fd == -1) {
-		ERROR(disk, "failed to open disk for reading");
+		ERROR(disk, "could not open special device");
 		return -1;
 	}
 
@@ -117,10 +145,20 @@ ufs_disk_fillout(struct uufsd *disk, const char *name)
 	disk->d_inoblock = NULL;
 	disk->d_inomin = 0;
 	disk->d_inomax = 0;
-	disk->d_name = name;
+	disk->d_mine = 0;
 	disk->d_ufs = 0;
 	disk->d_error = NULL;
 
+	if (oname != name) {
+		name = strdup(name);
+		if (name == NULL) {
+			ERROR(disk, "could not allocate memory for disk name");
+			return -1;
+		}
+		disk->d_mine |= MINE_NAME;
+	}
+	disk->d_name = name;
+
 	if (sbread(disk) == -1) {
 		ERROR(disk, "could not read superblock to fill out disk");
 		return -1;