The function `cache_tree_verify()` will `BUG()` whenever it finds that
the cache-tree extension of the index is corrupt. The function is thus
inherently untestable because the resulting call to `abort()` will be
detected by our testing framework and labelled an error. And rightfully
so: it shouldn't ever be possible to hit bugs, as they should indicate a
programming error rather than corruption of on-disk state.
Refactor the function to instead return error codes. This also ensures
that the function can be used e.g. by git-fsck(1) without the whole
process dying. Furthermore, this refactoring plugs some memory leaks
when returning early by creating a common exit path.
Signed-off-by: Patrick Steinhardt <ps@xxxxxx>
---
cache-tree.c | 97 +++++++++++++++++++++++++++++++++++---------------
cache-tree.h | 2 +-
read-cache.c | 5 +--
unpack-trees.c | 10 ++++--
4 files changed, 79 insertions(+), 35 deletions(-)
diff --git a/cache-tree.c b/cache-tree.c
index 50610c3f3c..4228b6fad4 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -2,6 +2,7 @@
#include "git-compat-util.h"
#include "environment.h"
+#include "gettext.h"
#include "hex.h"
#include "lockfile.h"
#include "tree.h"
@@ -864,15 +865,15 @@ int cache_tree_matches_traversal(struct cache_tree *root,
return 0;
}
-static void verify_one_sparse(struct index_state *istate,
- struct strbuf *path,
- int pos)
+static int verify_one_sparse(struct index_state *istate,
+ struct strbuf *path,
+ int pos)
{
struct cache_entry *ce = istate->cache[pos];
-
if (!S_ISSPARSEDIR(ce->ce_mode))
- BUG("directory '%s' is present in index, but not sparse",
- path->buf);
+ return error(_("directory '%s' is present in index, but not sparse"),
+ path->buf);
+ return 0;
}
/*
@@ -881,6 +882,7 @@ static void verify_one_sparse(struct index_state *istate,
* 1 - Restart verification - a call to ensure_full_index() freed the cache
* tree that is being verified and verification needs to be restarted from
* the new toplevel cache tree.
+ * -1 - Verification failed.
*/
static int verify_one(struct repository *r,
struct index_state *istate,
@@ -890,18 +892,23 @@ static int verify_one(struct repository *r,
int i, pos, len = path->len;
struct strbuf tree_buf = STRBUF_INIT;
struct object_id new_oid;
+ int ret;
for (i = 0; i < it->subtree_nr; i++) {
strbuf_addf(path, "%s/", it->down[i]->name);
- if (verify_one(r, istate, it->down[i]->cache_tree, path))
- return 1;
+ ret = verify_one(r, istate, it->down[i]->cache_tree, path);
+ if (ret)
+ goto out;
+
strbuf_setlen(path, len);
}
if (it->entry_count < 0 ||
/* no verification on tests (t7003) that replace trees */
- lookup_replace_object(r, &it->oid) != &it->oid)
- return 0;
+ lookup_replace_object(r, &it->oid) != &it->oid) {
+ ret = 0;
+ goto out;
+ }
if (path->len) {
/*
@@ -911,12 +918,14 @@ static int verify_one(struct repository *r,
*/
int is_sparse = istate->sparse_index;
pos = index_name_pos(istate, path->buf, path->len);
- if (is_sparse && !istate->sparse_index)
- return 1;
+ if (is_sparse && !istate->sparse_index) {
+ ret = 1;
+ goto out;
+ }
if (pos >= 0) {
- verify_one_sparse(istate, path, pos);
- return 0;
+ ret = verify_one_sparse(istate, path, pos);
+ goto out;
}
pos = -pos - 1;
@@ -934,16 +943,23 @@ static int verify_one(struct repository *r,
unsigned mode;
int entlen;
- if (ce->ce_flags & (CE_STAGEMASK | CE_INTENT_TO_ADD | CE_REMOVE))
- BUG("%s with flags 0x%x should not be in cache-tree",
- ce->name, ce->ce_flags);
+ if (ce->ce_flags & (CE_STAGEMASK | CE_INTENT_TO_ADD | CE_REMOVE)) {
+ ret = error(_("%s with flags 0x%x should not be in cache-tree"),
+ ce->name, ce->ce_flags);
+ goto out;
+ }
+
name = ce->name + path->len;
slash = strchr(name, '/');
if (slash) {
entlen = slash - name;
+
sub = find_subtree(it, ce->name + path->len, entlen, 0);
- if (!sub || sub->cache_tree->entry_count < 0)
- BUG("bad subtree '%.*s'", entlen, name);
+ if (!sub || sub->cache_tree->entry_count < 0) {
+ ret = error(_("bad subtree '%.*s'"), entlen, name);
+ goto out;
+ }
+
oid = &sub->cache_tree->oid;
mode = S_IFDIR;
i += sub->cache_tree->entry_count;
@@ -956,27 +972,50 @@ static int verify_one(struct repository *r,
strbuf_addf(&tree_buf, "%o %.*s%c", mode, entlen, name, '\0');
strbuf_add(&tree_buf, oid->hash, r->hash_algo->rawsz);
}
+
hash_object_file(r->hash_algo, tree_buf.buf, tree_buf.len, OBJ_TREE,
&new_oid);
- if (!oideq(&new_oid, &it->oid))
- BUG("cache-tree for path %.*s does not match. "
- "Expected %s got %s", len, path->buf,
- oid_to_hex(&new_oid), oid_to_hex(&it->oid));
+
+ if (!oideq(&new_oid, &it->oid)) {
+ ret = error(_("cache-tree for path %.*s does not match. "
+ "Expected %s got %s"), len, path->buf,
+ oid_to_hex(&new_oid), oid_to_hex(&it->oid));
+ goto out;
+ }
+
+ ret = 0;
+out:
strbuf_setlen(path, len);
strbuf_release(&tree_buf);
- return 0;
+ return ret;
}
-void cache_tree_verify(struct repository *r, struct index_state *istate)
+int cache_tree_verify(struct repository *r, struct index_state *istate)
{
struct strbuf path = STRBUF_INIT;
+ int ret;
- if (!istate->cache_tree)
- return;
- if (verify_one(r, istate, istate->cache_tree, &path)) {
+ if (!istate->cache_tree) {
+ ret = 0;
+ goto out;
+ }
+
+ ret = verify_one(r, istate, istate->cache_tree, &path);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
strbuf_reset(&path);
- if (verify_one(r, istate, istate->cache_tree, &path))
+
+ ret = verify_one(r, istate, istate->cache_tree, &path);
+ if (ret < 0)
+ goto out;
+ if (ret > 0)
BUG("ensure_full_index() called twice while verifying cache tree");
}
+
+ ret = 0;
+
+out:
strbuf_release(&path);
+ return ret;
}
diff --git a/cache-tree.h b/cache-tree.h
index faae88be63..b82c4963e7 100644
--- a/cache-tree.h
+++ b/cache-tree.h
@@ -33,7 +33,7 @@ struct cache_tree *cache_tree_read(const char *buffer, unsigned long size);
int cache_tree_fully_valid(struct cache_tree *);
int cache_tree_update(struct index_state *, int);
-void cache_tree_verify(struct repository *, struct index_state *);
+int cache_tree_verify(struct repository *, struct index_state *);
/* bitmasks to write_index_as_tree flags */
#define WRITE_TREE_MISSING_OK 1
diff --git a/read-cache.c b/read-cache.c
index 4e67dc182e..d72a3266b6 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -3331,8 +3331,9 @@ int write_locked_index(struct index_state *istate, struct lock_file *lock,
int new_shared_index, ret, test_split_index_env;
struct split_index *si = istate->split_index;
- if (git_env_bool("GIT_TEST_CHECK_CACHE_TREE", 0))
- cache_tree_verify(the_repository, istate);
+ if (git_env_bool("GIT_TEST_CHECK_CACHE_TREE", 0) &&
+ cache_tree_verify(the_repository, istate) < 0)
+ return -1;
if ((flags & SKIP_IF_UNCHANGED) && !istate->cache_changed) {
if (flags & COMMIT_LOCK)
diff --git a/unpack-trees.c b/unpack-trees.c
index 9a55cb6204..21cc197d47 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -2070,9 +2070,13 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
if (o->dst_index) {
move_index_extensions(&o->internal.result, o->src_index);
if (!ret) {
- if (git_env_bool("GIT_TEST_CHECK_CACHE_TREE", 0))
- cache_tree_verify(the_repository,
- &o->internal.result);
+ if (git_env_bool("GIT_TEST_CHECK_CACHE_TREE", 0) &&
+ cache_tree_verify(the_repository,
+ &o->internal.result) < 0) {
+ ret = -1;
+ goto done;
+ }
+
if (!o->skip_cache_tree_update &&
!cache_tree_fully_valid(o->internal.result.cache_tree))
cache_tree_update(&o->internal.result,
--
2.47.0.rc0.dirty
