When traversing the directory tree, the realpath of the `git_dir` is
required each time a nested repository is encountered to determine how
the nested repository should be treated. To prevent excessive resource
usage in pathological cases (e.g. many nested repositories, a long path,
symlinks, etc.), cache the realpath after the first usage until the
traversal is complete.
---
dir.c | 63 ++++++++++++++++++++++++++++++++++++++++-------------------
1 file changed, 43 insertions(+), 20 deletions(-)
diff --git a/dir.c b/dir.c
index e45e117875..45b89560fc 100644
--- a/dir.c
+++ b/dir.c
@@ -47,10 +47,22 @@ struct cached_dir {
struct untracked_cache_dir *ucd;
};
+/*
+ * Support data structure for the recursing into the directory tree.
+ */
+struct traversal_cache {
+ /*
+ * The realpath for the `git_dir` may be required in the recursion and is
+ * cached for repeated use.
+ */
+ char *real_gitdir;
+};
+
static enum path_treatment read_directory_recursive(struct dir_struct *dir,
struct index_state *istate, const char *path, int len,
struct untracked_cache_dir *untracked,
- int check_only, int stop_at_first_file, const struct pathspec *pathspec);
+ int check_only, int stop_at_first_file, const struct pathspec *pathspec,
+ struct traversal_cache *cache);
static int resolve_dtype(int dtype, struct index_state *istate,
const char *path, int len);
struct dirent *readdir_skip_dot_and_dotdot(DIR *dirp)
@@ -1852,7 +1864,8 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
struct index_state *istate,
struct untracked_cache_dir *untracked,
const char *dirname, int len, int baselen, int excluded,
- const struct pathspec *pathspec)
+ const struct pathspec *pathspec,
+ struct traversal_cache *cache)
{
/*
* WARNING: From this function, you can return path_recurse or you
@@ -1906,13 +1919,13 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
nested_repo = is_nonbare_repository_dir(&sb);
if (nested_repo) {
- char *real_dirname, *real_gitdir;
+ char *real_dirname;
strbuf_addstr(&sb, ".git");
real_dirname = real_pathdup(sb.buf, 1);
- real_gitdir = real_pathdup(the_repository->gitdir, 1);
+ if (!cache->real_gitdir)
+ cache->real_gitdir = real_pathdup(the_repository->gitdir, 1);
- nested_repo = !!strcmp(real_dirname, real_gitdir);
- free(real_gitdir);
+ nested_repo = !!strcmp(real_dirname, cache->real_gitdir);
free(real_dirname);
}
strbuf_release(&sb);
@@ -1944,7 +1957,7 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
return path_excluded;
if (read_directory_recursive(dir, istate, dirname, len,
- untracked, 1, 1, pathspec) == path_excluded)
+ untracked, 1, 1, pathspec, cache) == path_excluded)
return path_excluded;
return path_none;
@@ -2045,7 +2058,7 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
untracked = lookup_untracked(dir->untracked, untracked,
dirname + baselen, len - baselen);
state = read_directory_recursive(dir, istate, dirname, len, untracked,
- check_only, stop_early, pathspec);
+ check_only, stop_early, pathspec, cache);
/* There are a variety of reasons we may need to fixup the state... */
if (state == path_excluded) {
@@ -2242,7 +2255,8 @@ static enum path_treatment treat_path_fast(struct dir_struct *dir,
struct index_state *istate,
struct strbuf *path,
int baselen,
- const struct pathspec *pathspec)
+ const struct pathspec *pathspec,
+ struct traversal_cache *cache)
{
/*
* WARNING: From this function, you can return path_recurse or you
@@ -2264,7 +2278,7 @@ static enum path_treatment treat_path_fast(struct dir_struct *dir,
* with check_only set.
*/
return read_directory_recursive(dir, istate, path->buf, path->len,
- cdir->ucd, 1, 0, pathspec);
+ cdir->ucd, 1, 0, pathspec, cache);
/*
* We get path_recurse in the first run when
* directory_exists_in_index() returns index_nonexistent. We
@@ -2280,13 +2294,14 @@ static enum path_treatment treat_path(struct dir_struct *dir,
struct index_state *istate,
struct strbuf *path,
int baselen,
- const struct pathspec *pathspec)
+ const struct pathspec *pathspec,
+ struct traversal_cache *cache)
{
int has_path_in_index, dtype, excluded;
if (!cdir->d_name)
return treat_path_fast(dir, cdir, istate, path,
- baselen, pathspec);
+ baselen, pathspec, cache);
if (is_dot_or_dotdot(cdir->d_name) || !fspathcmp(cdir->d_name, ".git"))
return path_none;
strbuf_setlen(path, baselen);
@@ -2348,7 +2363,7 @@ static enum path_treatment treat_path(struct dir_struct *dir,
strbuf_addch(path, '/');
return treat_directory(dir, istate, untracked,
path->buf, path->len,
- baselen, excluded, pathspec);
+ baselen, excluded, pathspec, cache);
case DT_REG:
case DT_LNK:
if (pathspec &&
@@ -2549,7 +2564,8 @@ static void add_path_to_appropriate_result_list(struct dir_struct *dir,
static enum path_treatment read_directory_recursive(struct dir_struct *dir,
struct index_state *istate, const char *base, int baselen,
struct untracked_cache_dir *untracked, int check_only,
- int stop_at_first_file, const struct pathspec *pathspec)
+ int stop_at_first_file, const struct pathspec *pathspec,
+ struct traversal_cache *cache)
{
/*
* WARNING: Do NOT recurse unless path_recurse is returned from
@@ -2572,7 +2588,7 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
while (!read_cached_dir(&cdir)) {
/* check how the file or directory should be treated */
state = treat_path(dir, untracked, &cdir, istate, &path,
- baselen, pathspec);
+ baselen, pathspec, cache);
dir->visited_paths++;
if (state > dir_state)
@@ -2587,7 +2603,7 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
subdir_state =
read_directory_recursive(dir, istate, path.buf,
path.len, ud,
- check_only, stop_at_first_file, pathspec);
+ check_only, stop_at_first_file, pathspec, cache);
if (subdir_state > dir_state)
dir_state = subdir_state;
@@ -2661,7 +2677,8 @@ int check_dir_entry_contains(const struct dir_entry *out, const struct dir_entry
static int treat_leading_path(struct dir_struct *dir,
struct index_state *istate,
const char *path, int len,
- const struct pathspec *pathspec)
+ const struct pathspec *pathspec,
+ struct traversal_cache *cache)
{
struct strbuf sb = STRBUF_INIT;
struct strbuf subdir = STRBUF_INIT;
@@ -2713,7 +2730,8 @@ static int treat_leading_path(struct dir_struct *dir,
strbuf_reset(&subdir);
strbuf_add(&subdir, path+prevlen, baselen-prevlen);
cdir.d_name = subdir.buf;
- state = treat_path(dir, NULL, &cdir, istate, &sb, prevlen, pathspec);
+
+ state = treat_path(dir, NULL, &cdir, istate, &sb, prevlen, pathspec, cache);
if (state != path_recurse)
break; /* do not recurse into it */
@@ -2986,6 +3004,9 @@ int read_directory(struct dir_struct *dir, struct index_state *istate,
const char *path, int len, const struct pathspec *pathspec)
{
struct untracked_cache_dir *untracked;
+ struct traversal_cache cache = {
+ .real_gitdir = NULL,
+ };
trace2_region_enter("dir", "read_directory", istate->repo);
dir->visited_paths = 0;
@@ -3003,8 +3024,10 @@ int read_directory(struct dir_struct *dir, struct index_state *istate,
* e.g. prep_exclude()
*/
dir->untracked = NULL;
- if (!len || treat_leading_path(dir, istate, path, len, pathspec))
- read_directory_recursive(dir, istate, path, len, untracked, 0, 0, pathspec);
+ if (!len || treat_leading_path(dir, istate, path, len, pathspec, &cache)) {
+ read_directory_recursive(dir, istate, path, len, untracked, 0, 0, pathspec, &cache);
+ }
+ FREE_AND_NULL(cache.real_gitdir);
QSORT(dir->entries, dir->nr, cmp_dir_entry);
QSORT(dir->ignored, dir->ignored_nr, cmp_dir_entry);
--
2.36.0
