Btrfs-progs: btrfs-image: don't call pthread_join on IDs not present

If pthread_create fails in mdrestore_init, then number of threads
created could be less then num of threads option. Hence pass number of
successful pthread_create calls to mdrestore_destroy, so that we don't
call pthread_join on IDs not present when pthread_create fails.

metadump_init already had this fixed, but repeats code from
metadump_destroy. Reuse metadump_destroy by passing number of threads
created (successful pthread_create calls) and save repeated cleaup
code. Had to move metadump_destroy before metadump_init for obvious
reasons.

Signed-off-by: Rakesh Pandit <rakesh@tuxera.com>
Signed-off-by: David Sterba <dsterba@suse.cz>

diff --git a/btrfs-image.c b/btrfs-image.c
index cc8627c5d97b5b7e6c1f2e5ba02c9dd65d71c4c5..4c31e28cc039aa2a6b5e201afeca53f4544f752d 100644 (file)
--- a/btrfs-image.c
+++ b/btrfs-image.c
@@ -635,6 +635,35 @@ static void meta_cluster_init(struct metadump_struct *md, u64 start)
                           COMPRESS_ZLIB : COMPRESS_NONE;
 }
 
+static void metadump_destroy(struct metadump_struct *md, int num_threads)
+{
+       int i;
+       struct rb_node *n;
+
+       pthread_mutex_lock(&md->mutex);
+       md->done = 1;
+       pthread_cond_broadcast(&md->cond);
+       pthread_mutex_unlock(&md->mutex);
+
+       for (i = 0; i < num_threads; i++)
+               pthread_join(md->threads[i], NULL);
+
+       pthread_cond_destroy(&md->cond);
+       pthread_mutex_destroy(&md->mutex);
+
+       while ((n = rb_first(&md->name_tree))) {
+               struct name *name;
+
+               name = rb_entry(n, struct name, n);
+               rb_erase(n, &md->name_tree);
+               free(name->val);
+               free(name->sub);
+               free(name);
+       }
+       free(md->threads);
+       free(md->cluster);
+}
+
 static int metadump_init(struct metadump_struct *md, struct btrfs_root *root,
                         FILE *out, int num_threads, int compress_level,
                         int sanitize_names)
@@ -681,53 +710,12 @@ static int metadump_init(struct metadump_struct *md, struct btrfs_root *root,
                        break;
        }
 
-       if (ret) {
-               pthread_mutex_lock(&md->mutex);
-               md->done = 1;
-               pthread_cond_broadcast(&md->cond);
-               pthread_mutex_unlock(&md->mutex);
-
-               for (i--; i >= 0; i--)
-                       pthread_join(md->threads[i], NULL);
-
-               pthread_cond_destroy(&md->cond);
-               pthread_mutex_destroy(&md->mutex);
-               free(md->cluster);
-               free(md->threads);
-       }
+       if (ret)
+               metadump_destroy(md, i + 1);
 
        return ret;
 }
 
-static void metadump_destroy(struct metadump_struct *md)
-{
-       int i;
-       struct rb_node *n;
-
-       pthread_mutex_lock(&md->mutex);
-       md->done = 1;
-       pthread_cond_broadcast(&md->cond);
-       pthread_mutex_unlock(&md->mutex);
-
-       for (i = 0; i < md->num_threads; i++)
-               pthread_join(md->threads[i], NULL);
-
-       pthread_cond_destroy(&md->cond);
-       pthread_mutex_destroy(&md->mutex);
-
-       while ((n = rb_first(&md->name_tree))) {
-               struct name *name;
-
-               name = rb_entry(n, struct name, n);
-               rb_erase(n, &md->name_tree);
-               free(name->val);
-               free(name->sub);
-               free(name);
-       }
-       free(md->threads);
-       free(md->cluster);
-}
-
 static int write_zero(FILE *out, size_t size)
 {
        static char zero[BLOCK_SIZE];
@@ -1322,7 +1310,7 @@ out:
                fprintf(stderr, "Error flushing pending %d\n", ret);
        }
 
-       metadump_destroy(&metadump);
+       metadump_destroy(&metadump, num_threads);
 
        btrfs_free_path(path);
        ret = close_ctree(root);
@@ -1729,7 +1717,7 @@ out:
        pthread_exit(NULL);
 }
 
-static void mdrestore_destroy(struct mdrestore_struct *mdres)
+static void mdrestore_destroy(struct mdrestore_struct *mdres, int num_threads)
 {
        struct rb_node *n;
        int i;
@@ -1746,7 +1734,7 @@ static void mdrestore_destroy(struct mdrestore_struct *mdres)
        pthread_cond_broadcast(&mdres->cond);
        pthread_mutex_unlock(&mdres->mutex);
 
-       for (i = 0; i < mdres->num_threads; i++)
+       for (i = 0; i < num_threads; i++)
                pthread_join(mdres->threads[i], NULL);
 
        pthread_cond_destroy(&mdres->cond);
@@ -1787,7 +1775,7 @@ static int mdrestore_init(struct mdrestore_struct *mdres,
                        break;
        }
        if (ret)
-               mdrestore_destroy(mdres);
+               mdrestore_destroy(mdres, i + 1);
        return ret;
 }
 
@@ -2327,7 +2315,7 @@ static int __restore_metadump(const char *input, FILE *out, int old_restore,
                }
        }
 out:
-       mdrestore_destroy(&mdrestore);
+       mdrestore_destroy(&mdrestore, num_threads);
 failed_cluster:
        free(cluster);
 failed_info: