diff options
| -rw-r--r-- | fs/btrfs/extent_io.c | 32 | ||||
| -rw-r--r-- | fs/btrfs/tests/extent-io-tests.c | 9 |
2 files changed, 27 insertions, 14 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 8ff17bc30d5a..c467c664f600 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1593,21 +1593,25 @@ void find_first_clear_extent_bit(struct extent_io_tree *tree, u64 start, /* Find first extent with bits cleared */ while (1) { node = __etree_search(tree, start, &next, &prev, NULL, NULL); - if (!node) { + if (!node && !next && !prev) { + /* + * Tree is completely empty, send full range and let + * caller deal with it + */ + *start_ret = 0; + *end_ret = -1; + goto out; + } else if (!node && !next) { + /* + * We are past the last allocated chunk, set start at + * the end of the last extent. + */ + state = rb_entry(prev, struct extent_state, rb_node); + *start_ret = state->end + 1; + *end_ret = -1; + goto out; + } else if (!node) { node = next; - if (!node) { - /* - * We are past the last allocated chunk, - * set start at the end of the last extent. The - * device alloc tree should never be empty so - * prev is always set. - */ - ASSERT(prev); - state = rb_entry(prev, struct extent_state, rb_node); - *start_ret = state->end + 1; - *end_ret = -1; - goto out; - } } /* * At this point 'node' either contains 'start' or start is diff --git a/fs/btrfs/tests/extent-io-tests.c b/fs/btrfs/tests/extent-io-tests.c index 123d9a614357..df7ce874a74b 100644 --- a/fs/btrfs/tests/extent-io-tests.c +++ b/fs/btrfs/tests/extent-io-tests.c @@ -441,8 +441,17 @@ static int test_find_first_clear_extent_bit(void) int ret = -EINVAL; test_msg("running find_first_clear_extent_bit test"); + extent_io_tree_init(NULL, &tree, IO_TREE_SELFTEST, NULL); + /* Test correct handling of empty tree */ + find_first_clear_extent_bit(&tree, 0, &start, &end, CHUNK_TRIMMED); + if (start != 0 || end != -1) { + test_err( + "error getting a range from completely empty tree: start %llu end %llu", + start, end); + goto out; + } /* * Set 1M-4M alloc/discard and 32M-64M thus leaving a hole between * 4M-32M |