symlinks: remove PATH_MAX limitation

'git checkout' fails if a directory is longer than PATH_MAX, because the
lstat_cache in symlinks.c checks if the leading directory exists using
PATH_MAX-bounded string operations.

Remove the limitation by using strbuf instead.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/cache.h b/cache.h
index cc46be4e0fb2e8cdc69e48386f8233354a348818..b86eb84dbdb163543ec4c0dcf53860fe1d40d1ad 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -1068,12 +1068,16 @@ struct checkout {
 extern int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath);
 
 struct cache_def {
-       char path[PATH_MAX + 1];
-       int len;
+       struct strbuf path;
        int flags;
        int track_flags;
        int prefix_len_stat_func;
 };
+#define CACHE_DEF_INIT { STRBUF_INIT, 0, 0, 0 }
+static inline void cache_def_free(struct cache_def *cache)
+{
+       strbuf_release(&cache->path);
+}
 
 extern int has_symlink_leading_path(const char *name, int len);
 extern int threaded_has_symlink_leading_path(struct cache_def *, const char *, int);

diff --git a/preload-index.c b/preload-index.c
index 968ee25eae13f82fe4f93254d77660456732a5c6..79ce8a998b0008f9182fa127b85d63feff4592d0 100644 (file)
--- a/preload-index.c
+++ b/preload-index.c
@@ -37,9 +37,8 @@ static void *preload_thread(void *_data)
        struct thread_data *p = _data;
        struct index_state *index = p->index;
        struct cache_entry **cep = index->cache + p->offset;
-       struct cache_def cache;
+       struct cache_def cache = CACHE_DEF_INIT;
 
-       memset(&cache, 0, sizeof(cache));
        nr = p->nr;
        if (nr + p->offset > index->cache_nr)
                nr = index->cache_nr - p->offset;
@@ -64,6 +63,7 @@ static void *preload_thread(void *_data)
                        continue;
                ce_mark_uptodate(ce);
        } while (--nr > 0);
+       cache_def_free(&cache);
        return NULL;
 }
 

diff --git a/symlinks.c b/symlinks.c
index c2b41a85013eec87a412badc4097f364d547726d..5261e8cf499006c1d84fc42a3e96e4dee7f09ba1 100644 (file)
--- a/symlinks.c
+++ b/symlinks.c
@@ -35,12 +35,11 @@ static int longest_path_match(const char *name_a, int len_a,
        return match_len;
 }
 
-static struct cache_def default_cache;
+static struct cache_def default_cache = CACHE_DEF_INIT;
 
 static inline void reset_lstat_cache(struct cache_def *cache)
 {
-       cache->path[0] = '\0';
-       cache->len = 0;
+       strbuf_reset(&cache->path);
        cache->flags = 0;
        /*
         * The track_flags and prefix_len_stat_func members is only
@@ -73,7 +72,7 @@ static int lstat_cache_matchlen(struct cache_def *cache,
                                int prefix_len_stat_func)
 {
        int match_len, last_slash, last_slash_dir, previous_slash;
-       int save_flags, max_len, ret;
+       int save_flags, ret;
        struct stat st;
 
        if (cache->track_flags != track_flags ||
@@ -93,14 +92,14 @@ static int lstat_cache_matchlen(struct cache_def *cache,
                 * the 2 "excluding" path types.
                 */
                match_len = last_slash =
-                       longest_path_match(name, len, cache->path, cache->len,
-                                          &previous_slash);
+                       longest_path_match(name, len, cache->path.buf,
+                                          cache->path.len, &previous_slash);
                *ret_flags = cache->flags & track_flags & (FL_NOENT|FL_SYMLINK);
 
                if (!(track_flags & FL_FULLPATH) && match_len == len)
                        match_len = last_slash = previous_slash;
 
-               if (*ret_flags && match_len == cache->len)
+               if (*ret_flags && match_len == cache->path.len)
                        return match_len;
                /*
                 * If we now have match_len > 0, we would know that
@@ -121,21 +120,22 @@ static int lstat_cache_matchlen(struct cache_def *cache,
         */
        *ret_flags = FL_DIR;
        last_slash_dir = last_slash;
-       max_len = len < PATH_MAX ? len : PATH_MAX;
-       while (match_len < max_len) {
+       if (len > cache->path.len)
+               strbuf_grow(&cache->path, len - cache->path.len);
+       while (match_len < len) {
                do {
-                       cache->path[match_len] = name[match_len];
+                       cache->path.buf[match_len] = name[match_len];
                        match_len++;
-               } while (match_len < max_len && name[match_len] != '/');
-               if (match_len >= max_len && !(track_flags & FL_FULLPATH))
+               } while (match_len < len && name[match_len] != '/');
+               if (match_len >= len && !(track_flags & FL_FULLPATH))
                        break;
                last_slash = match_len;
-               cache->path[last_slash] = '\0';
+               cache->path.buf[last_slash] = '\0';
 
                if (last_slash <= prefix_len_stat_func)
-                       ret = stat(cache->path, &st);
+                       ret = stat(cache->path.buf, &st);
                else
-                       ret = lstat(cache->path, &st);
+                       ret = lstat(cache->path.buf, &st);
 
                if (ret) {
                        *ret_flags = FL_LSTATERR;
@@ -158,12 +158,11 @@ static int lstat_cache_matchlen(struct cache_def *cache,
         * for the moment!
         */
        save_flags = *ret_flags & track_flags & (FL_NOENT|FL_SYMLINK);
-       if (save_flags && last_slash > 0 && last_slash <= PATH_MAX) {
-               cache->path[last_slash] = '\0';
-               cache->len = last_slash;
+       if (save_flags && last_slash > 0) {
+               cache->path.buf[last_slash] = '\0';
+               cache->path.len = last_slash;
                cache->flags = save_flags;
-       } else if ((track_flags & FL_DIR) &&
-                  last_slash_dir > 0 && last_slash_dir <= PATH_MAX) {
+       } else if ((track_flags & FL_DIR) && last_slash_dir > 0) {
                /*
                 * We have a separate test for the directory case,
                 * since it could be that we have found a symlink or a
@@ -175,8 +174,8 @@ static int lstat_cache_matchlen(struct cache_def *cache,
                 * can still cache the path components before the last
                 * one (the found symlink or non-existing component).
                 */
-               cache->path[last_slash_dir] = '\0';
-               cache->len = last_slash_dir;
+               cache->path.buf[last_slash_dir] = '\0';
+               cache->path.len = last_slash_dir;
                cache->flags = FL_DIR;
        } else {
                reset_lstat_cache(cache);
@@ -273,21 +272,18 @@ static int threaded_has_dirs_only_path(struct cache_def *cache, const char *name
                FL_DIR;
 }
 
-static struct removal_def {
-       char path[PATH_MAX];
-       int len;
-} removal;
+static struct strbuf removal = STRBUF_INIT;
 
 static void do_remove_scheduled_dirs(int new_len)
 {
        while (removal.len > new_len) {
-               removal.path[removal.len] = '\0';
-               if (rmdir(removal.path))
+               removal.buf[removal.len] = '\0';
+               if (rmdir(removal.buf))
                        break;
                do {
                        removal.len--;
                } while (removal.len > new_len &&
-                        removal.path[removal.len] != '/');
+                        removal.buf[removal.len] != '/');
        }
        removal.len = new_len;
 }
@@ -297,7 +293,7 @@ void schedule_dir_for_removal(const char *name, int len)
        int match_len, last_slash, i, previous_slash;
 
        match_len = last_slash = i =
-               longest_path_match(name, len, removal.path, removal.len,
+               longest_path_match(name, len, removal.buf, removal.len,
                                   &previous_slash);
        /* Find last slash inside 'name' */
        while (i < len) {
@@ -317,11 +313,8 @@ void schedule_dir_for_removal(const char *name, int len)
         * If we go deeper down the directory tree, we only need to
         * save the new path components as we go down.
         */
-       if (match_len < last_slash) {
-               memcpy(&removal.path[match_len], &name[match_len],
-                      last_slash - match_len);
-               removal.len = last_slash;
-       }
+       if (match_len < last_slash)
+               strbuf_add(&removal, &name[match_len], last_slash - match_len);
 }
 
 void remove_scheduled_dirs(void)