[PATCH - mdadm] examine: tidy up some code.
From: NeilBrown <hidden>
Date: 2017-03-02 23:57:00
Subsystem:
the rest · Maintainer:
Linus Torvalds
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 <redacted>
Signed-off-by: NeilBrown <redacted>
---
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
Attachments
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