libblkid: overwrite existing hint

Addresses: https://github.com/karelzak/util-linux/issues/1161
Suggested-by:  Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/libblkid/src/probe.c b/libblkid/src/probe.c
index 113a5eec1f2c55ba6c3d96ecb36d9e9e4bdecc72..093fad1b64f4a799787c429bb1576c99d357db7f 100644 (file)
--- a/libblkid/src/probe.c
+++ b/libblkid/src/probe.c
@@ -2035,6 +2035,22 @@ void blkid_probe_use_wiper(blkid_probe pr, uint64_t off, uint64_t size)
        }
 }
 
+static struct blkid_hint *get_hint(blkid_probe pr, const char *name)
+{
+       struct list_head *p;
+
+       if (list_empty(&pr->hints))
+               return NULL;
+
+       list_for_each(p, &pr->hints) {
+               struct blkid_hint *h = list_entry(p, struct blkid_hint, hints);
+
+               if (h->name && strcmp(name, h->name) == 0)
+                       return h;
+       }
+       return NULL;
+}
+
 /**
  * blkid_probe_set_hint:
  * @pr: probe
@@ -2066,28 +2082,39 @@ int blkid_probe_set_hint(blkid_probe pr, const char *name, uint64_t value)
 
                if (errno || v == end || (end && *end))
                        goto done;
+       }
+
+       hint = get_hint(pr, n ? n : name);
+       if (hint) {
+               /* alter old hint */
+               hint->value = value;
+               DBG(LOWPROBE,
+                       ul_debug("updated hint '%s' to %"PRIu64"", hint->name, hint->value));
        } else {
-               n = strdup(name);
-               if (!n)
+               /* add a new hint */
+               if (!n) {
+                       n = strdup(name);
+                       if (!n)
+                               goto done;
+               }
+               hint = malloc(sizeof(*hint));
+               if (!hint)
                        goto done;
-       }
 
-       /* allocate info and space for data by one malloc call */
-       hint = malloc(sizeof(*hint));
-       if (!hint)
-               goto done;
+               hint->name = n;
+               hint->value = value;
 
-       INIT_LIST_HEAD(&hint->hints);
-       hint->name = n;
-       hint->value = value;
-       n = NULL;
-       list_add_tail(&hint->hints, &pr->hints);
+               INIT_LIST_HEAD(&hint->hints);
+               list_add_tail(&hint->hints, &pr->hints);
 
-       DBG(LOWPROBE,
-               ul_debug("new hint '%s' is %"PRIu64"", hint->name, hint->value));
+               DBG(LOWPROBE,
+                       ul_debug("new hint '%s' is %"PRIu64"", hint->name, hint->value));
+               n = NULL;
+       }
 done:
        free(n);
        free(v);
+
        if (!hint)
                return errno ? -errno : -EINVAL;
        return 0;
@@ -2095,21 +2122,13 @@ done:
 
 int blkid_probe_get_hint(blkid_probe pr, const char *name, uint64_t *value)
 {
-       struct list_head *p;
+       struct blkid_hint *h = get_hint(pr, name);
 
-       if (list_empty(&pr->hints))
+       if (!h)
                return -EINVAL;
-
-       list_for_each(p, &pr->hints) {
-               struct blkid_hint *h = list_entry(p, struct blkid_hint, hints);
-
-               if (h->name && strcmp(name, h->name) == 0) {
-                       if (value)
-                               *value = h->value;
-                       return 0;
-               }
-       }
-       return -EINVAL;
+       if (value)
+               *value = h->value;
+       return 0;
 }
 
 /**