libfstools: partname: several fixes

partname driver didn't allow mount_root to identify the filesystem
and hence the overlay filesystem state remained PENDING which lead
to overlay being cleared again at every reboot.
Fix that by setting v->blk early and, while at it, eliminate unneeded
strdup's by storing the full device paths in a union allowing accessing
the full path or the device name only.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

diff --git a/libfstools/partname.c b/libfstools/partname.c
index 9073a0d2c9968be31d61db0ffbdfdfcdc5a6d3b4..4560125879c6b29b982c4af7d3937d3be1e305f6 100644 (file)
--- a/libfstools/partname.c
+++ b/libfstools/partname.c
@@ -6,20 +6,33 @@
 
 const char *const block_dir_name = "/sys/class/block";
 
+struct devpath {
+       char prefix[5];
+       char device[11];
+};
+
 struct partname_volume {
        struct volume v;
-       char devname[16];
-       char parent_devname[16];
+       union {
+               char devpathstr[16];
+               struct devpath devpath;
+       } dev;
+
+       union {
+               char devpathstr[16];
+               struct devpath devpath;
+       } parent_dev;
 };
 
 static struct driver partname_driver;
 
 static int partname_volume_identify(struct volume *v)
 {
+       struct partname_volume *p = container_of(v, struct partname_volume, v);
        int ret = FS_NONE;
        FILE *f;
 
-       f = fopen(v->blk, "r");
+       f = fopen(p->dev.devpathstr, "r");
        if (!f)
                return ret;
 
@@ -34,23 +47,18 @@ static int partname_volume_init(struct volume *v)
 {
        struct partname_volume *p = container_of(v, struct partname_volume, v);
        char voldir[BUFLEN];
-       char voldev[BUFLEN];
-       char pdev[BUFLEN];
        unsigned int volsize;
 
-       snprintf(voldir, sizeof(voldir), "%s/%s", block_dir_name, p->devname);
+       snprintf(voldir, sizeof(voldir), "%s/%s", block_dir_name, p->dev.devpath.device);
 
        if (read_uint_from_file(voldir, "size", &volsize))
                return -1;
 
-       snprintf(voldev, sizeof(voldev), "/dev/%s", p->devname);
-       snprintf(pdev, sizeof(pdev), "/dev/%s", p->parent_devname);
-
        v->type = BLOCKDEV;
        v->size = volsize << 9; /* size is returned in sectors of 512 bytes */
-       v->blk = strdup(voldev);
+       v->blk = p->dev.devpathstr;
 
-       return block_volume_format(v, 0, pdev);
+       return block_volume_format(v, 0, p->parent_dev.devpathstr);
 }
 
 /* from procd/utils.c -> should go to libubox */
@@ -140,15 +148,21 @@ static struct volume *partname_volume_find(char *name)
        devname = strrchr(devname, '/') + 1;
 
        p = calloc(1, sizeof(*p));
-       strncpy(p->devname, devname, sizeof(p->devname));
+       memcpy(p->dev.devpath.prefix, "/dev/", sizeof(p->dev.devpath.prefix));
+       strncpy(p->dev.devpath.device, devname, sizeof(p->dev.devpath.device) - 1);
+       p->dev.devpath.device[sizeof(p->dev.devpath.device)-1] = '\0';
+
+       memcpy(p->parent_dev.devpath.prefix, "/dev/", sizeof(p->parent_dev.devpath.prefix));
        if (rootdev)
-               strncpy(p->parent_devname, rootdev, sizeof(p->devname));
+               strncpy(p->parent_dev.devpath.device, rootdev, sizeof(p->parent_dev.devpath.device) - 1);
        else
-               strncpy(p->parent_devname, rootdevname(devname), sizeof(p->devname));
+               strncpy(p->parent_dev.devpath.device, rootdevname(devname), sizeof(p->parent_dev.devpath.device) - 1);
+
+       p->parent_dev.devpath.device[sizeof(p->parent_dev.devpath.device)-1] = '\0';
 
-       p->devname[sizeof(p->devname)-1] = '\0';
        p->v.drv = &partname_driver;
-       p->v.name = strdup(namebuf);
+       p->v.blk = p->dev.devpathstr;
+       p->v.name = name;
 
        return &p->v;
 }