summaryrefslogtreecommitdiffstats
path: root/fs/btrfs/tests
diff options
context:
space:
mode:
authorLiu Bo <bo.li.liu@oracle.com>2018-01-05 12:51:13 -0700
committerDavid Sterba <dsterba@suse.com>2018-01-22 16:08:22 +0100
commitfd87526fada701295656b3c695ae20cb037fdd95 (patch)
treedca890161bd7f7dd97948779d520e490da660318 /fs/btrfs/tests
parent72b28077a20a6a1f14494602466c219241f45d89 (diff)
downloadlinux-fd87526fada701295656b3c695ae20cb037fdd95.tar.bz2
Btrfs: extent map selftest: buffered write vs dio read
This test case simulates the racy situation of buffered write vs dio read, and see if btrfs_get_extent() would return -EEXIST. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/tests')
-rw-r--r--fs/btrfs/tests/extent-map-tests.c74
1 files changed, 74 insertions, 0 deletions
diff --git a/fs/btrfs/tests/extent-map-tests.c b/fs/btrfs/tests/extent-map-tests.c
index e6f0dd18392e..16830bf88f46 100644
--- a/fs/btrfs/tests/extent-map-tests.c
+++ b/fs/btrfs/tests/extent-map-tests.c
@@ -182,6 +182,79 @@ out:
free_extent_map_tree(em_tree);
}
+static void __test_case_3(struct extent_map_tree *em_tree, u64 start)
+{
+ struct extent_map *em;
+ u64 len = SZ_4K;
+ int ret;
+
+ em = alloc_extent_map();
+ if (!em)
+ /* Skip this test on error. */
+ return;
+
+ /* Add [4K, 8K) */
+ em->start = SZ_4K;
+ em->len = SZ_4K;
+ em->block_start = SZ_4K;
+ em->block_len = SZ_4K;
+ ret = add_extent_mapping(em_tree, em, 0);
+ ASSERT(ret == 0);
+ free_extent_map(em);
+
+ em = alloc_extent_map();
+ if (!em)
+ goto out;
+
+ /* Add [0, 16K) */
+ em->start = 0;
+ em->len = SZ_16K;
+ em->block_start = 0;
+ em->block_len = SZ_16K;
+ ret = btrfs_add_extent_mapping(em_tree, &em, start, len);
+ if (ret)
+ test_msg("case3 [0x%llx 0x%llx): ret %d\n",
+ start, start + len, ret);
+ /*
+ * Since bytes within em are contiguous, em->block_start is identical to
+ * em->start.
+ */
+ if (em &&
+ (start < em->start || start + len > extent_map_end(em) ||
+ em->start != em->block_start || em->len != em->block_len))
+ test_msg(
+"case3 [0x%llx 0x%llx): ret %d em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx)\n",
+ start, start + len, ret, em->start, em->len,
+ em->block_start, em->block_len);
+ free_extent_map(em);
+out:
+ /* free memory */
+ free_extent_map_tree(em_tree);
+}
+
+/*
+ * Test scenario:
+ *
+ * Suppose that no extent map has been loaded into memory yet.
+ * There is a file extent [0, 16K), two jobs are running concurrently
+ * against it, t1 is buffered writing to [4K, 8K) and t2 is doing dio
+ * read from [0, 4K) or [8K, 12K) or [12K, 16K).
+ *
+ * t1 goes ahead of t2 and adds em [4K, 8K) into tree.
+ *
+ * t1 t2
+ * cow_file_range() btrfs_get_extent()
+ * -> lookup_extent_mapping()
+ * -> add_extent_mapping()
+ * -> add_extent_mapping()
+ */
+static void test_case_3(struct extent_map_tree *em_tree)
+{
+ __test_case_3(em_tree, 0);
+ __test_case_3(em_tree, SZ_8K);
+ __test_case_3(em_tree, (12 * 1024ULL));
+}
+
int btrfs_test_extent_map()
{
struct extent_map_tree *em_tree;
@@ -197,6 +270,7 @@ int btrfs_test_extent_map()
test_case_1(em_tree);
test_case_2(em_tree);
+ test_case_3(em_tree);
kfree(em_tree);
return 0;