From patchwork Wed Jun 26 12:11:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Vivier X-Patchwork-Id: 11017555 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5370D1398 for ; Wed, 26 Jun 2019 12:13:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 406EB2862A for ; Wed, 26 Jun 2019 12:13:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 34C9828774; Wed, 26 Jun 2019 12:13:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 980412862A for ; Wed, 26 Jun 2019 12:13:39 +0000 (UTC) Received: from localhost ([::1]:39456 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hg6ny-0007Sa-Ut for patchwork-qemu-devel@patchwork.kernel.org; Wed, 26 Jun 2019 08:13:39 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49913) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hg6mV-0005bP-GV for qemu-devel@nongnu.org; Wed, 26 Jun 2019 08:12:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hg6mT-0000pL-Le for qemu-devel@nongnu.org; Wed, 26 Jun 2019 08:12:07 -0400 Received: from mout.kundenserver.de ([217.72.192.73]:58451) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hg6mT-0000l5-36 for qemu-devel@nongnu.org; Wed, 26 Jun 2019 08:12:05 -0400 Received: from localhost.localdomain ([78.238.229.36]) by mrelayeu.kundenserver.de (mreue109 [212.227.15.183]) with ESMTPSA (Nemesis) id 1MAwPf-1hqo1q0ucL-00BJMb; Wed, 26 Jun 2019 14:11:47 +0200 From: Laurent Vivier To: qemu-devel@nongnu.org Date: Wed, 26 Jun 2019 14:11:34 +0200 Message-Id: <20190626121139.19114-2-laurent@vivier.eu> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190626121139.19114-1-laurent@vivier.eu> References: <20190626121139.19114-1-laurent@vivier.eu> MIME-Version: 1.0 X-Provags-ID: V03:K1:ui0tnn6wr8frkgkNKUI2A5bMESmhU0/bggWXerM4U3JzIGWhPzj SDcYe/WEQeD3/6u7R06IPk1+uipyZsz0qKDf5ERxSaW+fNAOffzhwlCyQNJI7ekAx2w10G0 G3DShJuZ1DUcr1H0M1dngBE1+KsTlZWE/hQOF2Z4+qtvKkSkyB5pufTSsAYMZ0KjSFQcf4J FzaH67N/4WI5rNa7o5LRg== X-UI-Out-Filterresults: notjunk:1;V03:K0:v7FjBSlm+fk=:y7w1AUsHyS4jQbtYxiop6t ulz3tGZi8uENGzaGKXaS/M+v1GdW6Rpcc6ae76LHK4SkwBwMXKGFC1pZ8rlKE1LV7WZJQbG0J ePTG5pVH7O/nWvRiBHkP6zYRvGvTx9tdldNIZO8FooxIYHTu8aaJ2xLZiABuPH4LHCrOd6HyO 6YGwaPavOFC+k8ujjpcPlZ2IJze20Lo2W82MBBlqFKHdjlnYqyMY5M0CLKK21MgO44/7Q1CAy YiQj5j3qKv8Prz8s8fvyxeBY12IDzSYx4+zVFQtNXFb2OcDaQh/4ZqDxVKQzcJTiT1jTPq4Ei QITzHOZUZGxdeqKtPo+LS3PbdtvIg755+gi2bhvuKmOtWMzeEJyQ8O1maAtEF4MrMb6J+3rf5 bCCZFcKCz4s1hH5xA0lD81C4G8s0/Jy91vCRY1/2Iu42+yZFa01sKf9kHRKz+g7EuWaBnKTOz fqshisatzc6yhDP1voW3U4INQfTzLO9PcMrVCXpDByiU6MnmG3sFVtQptH/2m8YcvuBIPwafD 4hinh1RB5HzKf9vx6E3V96uHs+kJco0UUAG7+U6x6Ho+Oq+1i/9KBcvbjR0pI8iB7WZnqVjse seELPfsE90NaxpyJ+Sino6Xk+TUQMdFy+locWnfeyBX9GtXNNoTn6UABMy7EK9P1L+tLAHNEq WHHgWF/yMZaZaHcZVJOCXyQC4r+rTDLH3G1y/+Yprq9bIEe8YNzdS0RIjvZfNokY9VO9W+Dz3 0YpzSXk714yTeZTjA4ho+hWNWzWqn5luZVl+Bg== X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 217.72.192.73 Subject: [Qemu-devel] [PULL 1/6] util/path: Do not cache all filenames at startup X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Riku Voipio , Richard Henderson , Laurent Vivier Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Richard Henderson If one uses -L $PATH to point to a full chroot, the startup time is significant. In addition, the existing probing algorithm fails to handle symlink loops. Instead, probe individual paths on demand. Cache both positive and negative results within $PATH, so that any one filename is probed only once. Use glib filename functions for clarity. Signed-off-by: Richard Henderson Reviewed-by: Laurent Vivier Tested-by: Laurent Vivier Message-Id: <20190519201953.20161-2-richard.henderson@linaro.org> Signed-off-by: Laurent Vivier --- util/path.c | 193 ++++++++++++---------------------------------------- 1 file changed, 43 insertions(+), 150 deletions(-) diff --git a/util/path.c b/util/path.c index 7f9fc272fbb3..8e174eb43642 100644 --- a/util/path.c +++ b/util/path.c @@ -8,170 +8,63 @@ #include #include "qemu/cutils.h" #include "qemu/path.h" +#include "qemu/thread.h" -struct pathelem -{ - /* Name of this, eg. lib */ - char *name; - /* Full path name, eg. /usr/gnemul/x86-linux/lib. */ - char *pathname; - struct pathelem *parent; - /* Children */ - unsigned int num_entries; - struct pathelem *entries[0]; -}; - -static struct pathelem *base; - -/* First N chars of S1 match S2, and S2 is N chars long. */ -static int strneq(const char *s1, unsigned int n, const char *s2) -{ - unsigned int i; - - for (i = 0; i < n; i++) - if (s1[i] != s2[i]) - return 0; - return s2[i] == 0; -} - -static struct pathelem *add_entry(struct pathelem *root, const char *name, - unsigned type); +static const char *base; +static GHashTable *hash; +static QemuMutex lock; -static struct pathelem *new_entry(const char *root, - struct pathelem *parent, - const char *name) -{ - struct pathelem *new = g_malloc(sizeof(*new)); - new->name = g_strdup(name); - new->pathname = g_strdup_printf("%s/%s", root, name); - new->num_entries = 0; - return new; -} - -#define streq(a,b) (strcmp((a), (b)) == 0) - -/* Not all systems provide this feature */ -#if defined(DT_DIR) && defined(DT_UNKNOWN) && defined(DT_LNK) -# define dirent_type(dirent) ((dirent)->d_type) -# define is_dir_maybe(type) \ - ((type) == DT_DIR || (type) == DT_UNKNOWN || (type) == DT_LNK) -#else -# define dirent_type(dirent) (1) -# define is_dir_maybe(type) (type) -#endif - -static struct pathelem *add_dir_maybe(struct pathelem *path) +void init_paths(const char *prefix) { - DIR *dir; - - if ((dir = opendir(path->pathname)) != NULL) { - struct dirent *dirent; - - while ((dirent = readdir(dir)) != NULL) { - if (!streq(dirent->d_name,".") && !streq(dirent->d_name,"..")){ - path = add_entry(path, dirent->d_name, dirent_type(dirent)); - } - } - closedir(dir); + if (prefix[0] == '\0' || !strcmp(prefix, "/")) { + return; } - return path; -} - -static struct pathelem *add_entry(struct pathelem *root, const char *name, - unsigned type) -{ - struct pathelem **e; - - root->num_entries++; - - root = g_realloc(root, sizeof(*root) - + sizeof(root->entries[0])*root->num_entries); - e = &root->entries[root->num_entries-1]; - *e = new_entry(root->pathname, root, name); - if (is_dir_maybe(type)) { - *e = add_dir_maybe(*e); + if (prefix[0] == '/') { + base = g_strdup(prefix); + } else { + char *cwd = g_get_current_dir(); + base = g_build_filename(cwd, prefix, NULL); + g_free(cwd); } - return root; -} - -/* This needs to be done after tree is stabilized (ie. no more reallocs!). */ -static void set_parents(struct pathelem *child, struct pathelem *parent) -{ - unsigned int i; - - child->parent = parent; - for (i = 0; i < child->num_entries; i++) - set_parents(child->entries[i], child); + hash = g_hash_table_new(g_str_hash, g_str_equal); + qemu_mutex_init(&lock); } -/* FIXME: Doesn't handle DIR/.. where DIR is not in emulated dir. */ -static const char * -follow_path(const struct pathelem *cursor, const char *name) -{ - unsigned int i, namelen; - - name += strspn(name, "/"); - namelen = strcspn(name, "/"); - - if (namelen == 0) - return cursor->pathname; - - if (strneq(name, namelen, "..")) - return follow_path(cursor->parent, name + namelen); - - if (strneq(name, namelen, ".")) - return follow_path(cursor, name + namelen); - - for (i = 0; i < cursor->num_entries; i++) - if (strneq(name, namelen, cursor->entries[i]->name)) - return follow_path(cursor->entries[i], name + namelen); - - /* Not found */ - return NULL; -} - -void init_paths(const char *prefix) +/* Look for path in emulation dir, otherwise return name. */ +const char *path(const char *name) { - char pref_buf[PATH_MAX]; - - if (prefix[0] == '\0' || - !strcmp(prefix, "/")) - return; + gpointer key, value; + const char *ret; - if (prefix[0] != '/') { - char *cwd = getcwd(NULL, 0); - size_t pref_buf_len = sizeof(pref_buf); + /* Only do absolute paths: quick and dirty, but should mostly be OK. */ + if (!base || !name || name[0] != '/') { + return name; + } - if (!cwd) - abort(); - pstrcpy(pref_buf, sizeof(pref_buf), cwd); - pstrcat(pref_buf, pref_buf_len, "/"); - pstrcat(pref_buf, pref_buf_len, prefix); - free(cwd); - } else - pstrcpy(pref_buf, sizeof(pref_buf), prefix + 1); + qemu_mutex_lock(&lock); - base = new_entry("", NULL, pref_buf); - base = add_dir_maybe(base); - if (base->num_entries == 0) { - g_free(base->pathname); - g_free(base->name); - g_free(base); - base = NULL; + /* Have we looked up this file before? */ + if (g_hash_table_lookup_extended(hash, name, &key, &value)) { + ret = value ? value : name; } else { - set_parents(base, base); + char *save = g_strdup(name); + char *full = g_build_filename(base, name, NULL); + + /* Look for the path; record the result, pass or fail. */ + if (access(full, F_OK) == 0) { + /* Exists. */ + g_hash_table_insert(hash, save, full); + ret = full; + } else { + /* Does not exist. */ + g_free(full); + g_hash_table_insert(hash, save, NULL); + ret = name; + } } -} - -/* Look for path in emulation dir, otherwise return name. */ -const char *path(const char *name) -{ - /* Only do absolute paths: quick and dirty, but should mostly be OK. - Could do relative by tracking cwd. */ - if (!base || !name || name[0] != '/') - return name; - return follow_path(base, name) ?: name; + qemu_mutex_unlock(&lock); + return ret; }