Fix up logic for handling short data blocks.

This fixes a crash when there are writes that are not a multiple of the
block size.

diff --git a/bluesky/file.c b/bluesky/file.c
index 3be40f0..ae49d71 100644 (file)
--- a/bluesky/file.c
+++ b/bluesky/file.c
@@ -63,7 +63,23 @@ void bluesky_file_truncate(BlueSkyInode *inode, uint64_t size)
     if (blocks > inode->blocks->len) {
         /* Need to add new blocks to the end of a file.  New block structures
          * are automatically zeroed, which initializes them to be pointers to
-         * zero blocks so we don't need to do any more work. */
+         * zero blocks so we don't need to do any more work.  If the
+         * previously-last block in the file is smaller than
+         * BLUESKY_BLOCK_SIZE, extend it to full size. */
+        if (inode->blocks->len > 0) {
+            BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock,
+                                             inode->blocks->len - 1);
+
+            if (b->type != BLUESKY_BLOCK_ZERO
+                    && b->data->len < BLUESKY_BLOCK_SIZE) {
+                bluesky_block_touch(inode, inode->blocks->len - 1);
+                gsize old_size = b->data->len;
+                bluesky_string_resize(b->data, BLUESKY_BLOCK_SIZE);
+                memset(&b->data->data[old_size], 0,
+                       BLUESKY_BLOCK_SIZE - old_size);
+            }
+        }
+
         g_array_set_size(inode->blocks, blocks);
     } else if (blocks < inode->blocks->len) {
         /* Delete blocks from a file.  Must reclaim memory. */
@@ -75,8 +91,8 @@ void bluesky_file_truncate(BlueSkyInode *inode, uint64_t size)
         g_array_set_size(inode->blocks, blocks);
     }
 
-    /* Ensure the last block of the file is properly sized.  If the block is
-     * extended, newly-added bytes must be zeroed. */
+    /* Ensure the new last block of the file is properly sized.  If the block
+     * is extended, newly-added bytes must be zeroed. */
     if (blocks > 0) {
         BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock,
                                          blocks - 1);

diff --git a/bluesky/util.c b/bluesky/util.c
index 7f977a6..eab6a14 100644 (file)
--- a/bluesky/util.c
+++ b/bluesky/util.c
@@ -109,4 +109,5 @@ void bluesky_string_resize(BlueSkyRCStr *string, gsize len)
         return;
 
     string->data = g_realloc(string->data, len);
+    string->len = len;
 }