examine: tidy up some code.

Michael Shigorin reports that the 'lcc' compiler isn't able
to deduce that 'st' must be initialized in

		if (c->SparcAdjust)
			st->ss->update_super(st, NULL, "sparc2.2",

just because the only times it isn't initialised, 'err' is set non-zero.

This results in a 'possibly uninitialised' warning.
While there is no bug in the code, this does suggest that maybe
the code could be made more obviously correct.

So this patch:
 1/ moves the "err" variable inside the for loop, so an error in
    one device doesn't stop the other devices from being processed
 2/ calls 'continue' early if the device cannot be opened, so that
    a level of indent can be removed, and so that it is clear that
    'st' is always initialised before being used
 3/ frees 'st' if an error occured in load_super or load_container.

Reported-by: Michael Shigorin <mike@altlinux.org>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@gmail.com>

diff --git a/Examine.c b/Examine.c
index 953b8eee236008127f590ac77cad263e0d9d360d..7013480d6dd80846cc2f464d3ba23c9e8e21284d 100644 (file)
--- a/Examine.c
+++ b/Examine.c
@@ -53,7 +53,6 @@ int Examine(struct mddev_dev *devlist,
         */
        int fd;
        int rv = 0;
-       int err = 0;
 
        struct array {
                struct supertype *st;
@@ -66,6 +65,8 @@ int Examine(struct mddev_dev *devlist,
        for (; devlist ; devlist = devlist->next) {
                struct supertype *st;
                int have_container = 0;
+               int err = 0;
+               int container = 0;
 
                fd = dev_open(devlist->devname, O_RDONLY);
                if (fd < 0) {
@@ -74,44 +75,46 @@ int Examine(struct mddev_dev *devlist,
                                       devlist->devname, strerror(errno));
                                rv = 1;
                        }
-                       err = 1;
+                       continue;
                }
-               else {
-                       int container = 0;
-                       if (forcest)
-                               st = dup_super(forcest);
-                       else if (must_be_container(fd)) {
-                               /* might be a container */
-                               st = super_by_fd(fd, NULL);
-                               container = 1;
-                       } else
-                               st = guess_super(fd);
-                       if (st) {
-                               err = 1;
-                               st->ignore_hw_compat = 1;
-                               if (!container)
-                                       err = st->ss->load_super(st, fd,
-                                                                (c->brief||c->scan) ? NULL
-                                                                :devlist->devname);
-                               if (err && st->ss->load_container) {
-                                       err = st->ss->load_container(st, fd,
-                                                                (c->brief||c->scan) ? NULL
-                                                                :devlist->devname);
-                                       if (!err)
-                                               have_container = 1;
-                               }
-                               st->ignore_hw_compat = 0;
-                       } else {
-                               if (!c->brief) {
-                                       pr_err("No md superblock detected on %s.\n", devlist->devname);
-                                       rv = 1;
-                               }
-                               err = 1;
+
+               if (forcest)
+                       st = dup_super(forcest);
+               else if (must_be_container(fd)) {
+                       /* might be a container */
+                       st = super_by_fd(fd, NULL);
+                       container = 1;
+               } else
+                       st = guess_super(fd);
+               if (st) {
+                       err = 1;
+                       st->ignore_hw_compat = 1;
+                       if (!container)
+                               err = st->ss->load_super(st, fd,
+                                                        (c->brief||c->scan) ? NULL
+                                                        :devlist->devname);
+                       if (err && st->ss->load_container) {
+                               err = st->ss->load_container(st, fd,
+                                                            (c->brief||c->scan) ? NULL
+                                                            :devlist->devname);
+                               if (!err)
+                                       have_container = 1;
                        }
-                       close(fd);
+                       st->ignore_hw_compat = 0;
+               } else {
+                       if (!c->brief) {
+                               pr_err("No md superblock detected on %s.\n", devlist->devname);
+                               rv = 1;
+                       }
+                       err = 1;
                }
-               if (err)
+               close(fd);
+
+               if (err) {
+                       if (st)
+                               st->ss->free_super(st);
                        continue;
+               }
 
                if (c->SparcAdjust)
                        st->ss->update_super(st, NULL, "sparc2.2",
@@ -121,7 +124,7 @@ int Examine(struct mddev_dev *devlist,
                if (c->brief && st->ss->brief_examine_super == NULL) {
                        if (!c->scan)
                                pr_err("No brief listing for %s on %s\n",
-                                       st->ss->name, devlist->devname);
+                                      st->ss->name, devlist->devname);
                } else if (c->brief) {
                        struct array *ap;
                        char *d;