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@xxxxxxxxxxxx>
Signed-off-by: NeilBrown <neilb@xxxxxxxx>
---
Examine.c | 75 +++++++++++++++++++++++++++++++++------------------------------
1 file changed, 39 insertions(+), 36 deletions(-)
diff --git a/Examine.c b/Examine.c
index 953b8eee2360..7013480d6dd8 100644
--- 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;
--
2.11.0
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