From aa79636fe70247a19648d73e52a7774536100567 Mon Sep 17 00:00:00 2001 From: Victoria Dye Date: Mon, 9 Oct 2023 21:58:55 +0000 Subject: [PATCH] dir.[ch]: add 'follow_symlink' arg to 'get_dtype' Add a 'follow_symlink' boolean option to 'get_type()'. If 'follow_symlink' is enabled, DT_LNK (in addition to DT_UNKNOWN) d_types triggers the stat-based d_type resolution, using 'stat' instead of 'lstat' to get the type of the followed symlink. Note that symlinks are not followed recursively, so a symlink pointing to another symlink will still resolve to DT_LNK. Update callers in 'diagnose.c' to specify 'follow_symlink = 0' to preserve current behavior. Signed-off-by: Victoria Dye Signed-off-by: Junio C Hamano --- diagnose.c | 6 +++--- dir.c | 13 +++++++++---- dir.h | 7 ++++++- 3 files changed, 18 insertions(+), 8 deletions(-) diff --git a/diagnose.c b/diagnose.c index fc4d344bd6..4d096c857f 100644 --- a/diagnose.c +++ b/diagnose.c @@ -81,7 +81,7 @@ static int count_files(struct strbuf *path) return 0; while ((e = readdir_skip_dot_and_dotdot(dir)) != NULL) - if (get_dtype(e, path) == DT_REG) + if (get_dtype(e, path, 0) == DT_REG) count++; closedir(dir); @@ -110,7 +110,7 @@ static void loose_objs_stats(struct strbuf *buf, const char *path) base_path_len = count_path.len; while ((e = readdir_skip_dot_and_dotdot(dir)) != NULL) - if (get_dtype(e, &count_path) == DT_DIR && + if (get_dtype(e, &count_path, 0) == DT_DIR && strlen(e->d_name) == 2 && !hex_to_bytes(&c, e->d_name, 1)) { strbuf_setlen(&count_path, base_path_len); @@ -155,7 +155,7 @@ static int add_directory_to_archiver(struct strvec *archiver_args, strbuf_add_absolute_path(&abspath, at_root ? "." : path); strbuf_addch(&abspath, '/'); - dtype = get_dtype(e, &abspath); + dtype = get_dtype(e, &abspath, 0); strbuf_setlen(&buf, len); strbuf_addstr(&buf, e->d_name); diff --git a/dir.c b/dir.c index 5e01af3a25..16fdb03f2a 100644 --- a/dir.c +++ b/dir.c @@ -2235,19 +2235,24 @@ static int get_index_dtype(struct index_state *istate, return DT_UNKNOWN; } -unsigned char get_dtype(struct dirent *e, struct strbuf *path) +unsigned char get_dtype(struct dirent *e, struct strbuf *path, + int follow_symlink) { struct stat st; unsigned char dtype = DTYPE(e); size_t base_path_len; - if (dtype != DT_UNKNOWN) + if (dtype != DT_UNKNOWN && !(follow_symlink && dtype == DT_LNK)) return dtype; - /* d_type unknown in dirent, try to fall back on lstat results */ + /* + * d_type unknown or unfollowed symlink, try to fall back on [l]stat + * results. If [l]stat fails, explicitly set DT_UNKNOWN. + */ base_path_len = path->len; strbuf_addstr(path, e->d_name); - if (lstat(path->buf, &st)) + if ((follow_symlink && stat(path->buf, &st)) || + (!follow_symlink && lstat(path->buf, &st))) goto cleanup; /* determine d_type from st_mode */ diff --git a/dir.h b/dir.h index 28c630ce80..98aa85fcc0 100644 --- a/dir.h +++ b/dir.h @@ -368,11 +368,16 @@ struct dirent *readdir_skip_dot_and_dotdot(DIR *dirp); * stat.st_mode using the path to the dirent's containing directory (path) and * the name of the dirent itself. * + * If 'follow_symlink' is 1, this function will attempt to follow DT_LNK types + * using 'stat'. Links are *not* followed recursively, so a symlink pointing + * to another symlink will still resolve to 'DT_LNK'. + * * Note that 'path' is assumed to have a trailing slash. It is also modified * in-place during the execution of the function, but is then reverted to its * original value before returning. */ -unsigned char get_dtype(struct dirent *e, struct strbuf *path); +unsigned char get_dtype(struct dirent *e, struct strbuf *path, + int follow_symlink); /*Count the number of slashes for string s*/ int count_slashes(const char *s);