From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Yauheni Kaliuta To: Lucas De Marchi Cc: linux-modules Subject: [PATCHv2 2/4] depmod: rewrite depmod modules search with scratchbuf Date: Tue, 9 May 2017 22:09:22 +0300 Message-Id: <20170509190924.9087-3-yauheni.kaliuta@redhat.com> In-Reply-To: <20170509190924.9087-1-yauheni.kaliuta@redhat.com> References: <20170509190924.9087-1-yauheni.kaliuta@redhat.com> List-ID: The recursive search code used used pretty big, PATH_MAX, automatic storage buffer for the module directory scanning. Some time ago there was scratchbuf implemented, which dynamically reallocates its buffer on demand. The patch takes it in use for the scanning code also. The initial size is hardcoded to 256 bytes which sounds good enough for most usecases so there should be not many reallocations. Signed-off-by: Yauheni Kaliuta --- tools/depmod.c | 33 +++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) diff --git a/tools/depmod.c b/tools/depmod.c index cfed864ff6c1..a9a02bbb1aa7 100644 --- a/tools/depmod.c +++ b/tools/depmod.c @@ -1108,10 +1108,11 @@ add: return 0; } -static int depmod_modules_search_dir(struct depmod *depmod, DIR *d, size_t baselen, char *path) +static int depmod_modules_search_dir(struct depmod *depmod, DIR *d, size_t baselen, struct scratchbuf *s_path) { struct dirent *de; int err = 0, dfd = dirfd(d); + char *path; while ((de = readdir(d)) != NULL) { const char *name = de->d_name; @@ -1124,11 +1125,13 @@ static int depmod_modules_search_dir(struct depmod *depmod, DIR *d, size_t basel if (streq(name, "build") || streq(name, "source")) continue; namelen = strlen(name); - if (baselen + namelen + 2 >= PATH_MAX) { - path[baselen] = '\0'; - ERR("path is too long %s%s\n", path, name); + if (scratchbuf_alloc(s_path, baselen + namelen + 2) < 0) { + err = -ENOMEM; + ERR("No memory\n"); continue; } + + path = scratchbuf_str(s_path); memcpy(path + baselen, name, namelen + 1); if (de->d_type == DT_REG) @@ -1154,10 +1157,6 @@ static int depmod_modules_search_dir(struct depmod *depmod, DIR *d, size_t basel if (is_dir) { int fd; DIR *subdir; - if (baselen + namelen + 2 + NAME_MAX >= PATH_MAX) { - ERR("directory path is too long %s\n", path); - continue; - } fd = openat(dfd, name, O_RDONLY); if (fd < 0) { ERR("openat(%d, %s, O_RDONLY): %m\n", @@ -1174,7 +1173,7 @@ static int depmod_modules_search_dir(struct depmod *depmod, DIR *d, size_t basel path[baselen + namelen + 1] = '\0'; err = depmod_modules_search_dir(depmod, subdir, baselen + namelen + 1, - path); + s_path); closedir(subdir); } else { err = depmod_modules_search_file(depmod, baselen, @@ -1187,14 +1186,16 @@ static int depmod_modules_search_dir(struct depmod *depmod, DIR *d, size_t basel err = 0; /* ignore errors */ } } - return err; } static int depmod_modules_search_path(struct depmod *depmod, const char *path) { - char path_buf[PATH_MAX]; + char buf[256]; + _cleanup_(scratchbuf_release) struct scratchbuf s_path_buf = + SCRATCHBUF_INITIALIZER(buf); + char *path_buf; DIR *d; size_t baselen; int err; @@ -1207,12 +1208,20 @@ static int depmod_modules_search_path(struct depmod *depmod, } baselen = strlen(path); + + if (scratchbuf_alloc(&s_path_buf, baselen + 2) < 0) { + err = -ENOMEM; + goto out; + } + path_buf = scratchbuf_str(&s_path_buf); + memcpy(path_buf, path, baselen); path_buf[baselen] = '/'; baselen++; path_buf[baselen] = '\0'; - err = depmod_modules_search_dir(depmod, d, baselen, path_buf); + err = depmod_modules_search_dir(depmod, d, baselen, &s_path_buf); +out: closedir(d); return err; } -- 2.12.2.639.g584f8975d2d9