From nobody Mon Jun 22 23:55:42 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9220FC433F5 for ; Tue, 15 Mar 2022 06:06:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345115AbiCOGIA (ORCPT ); Tue, 15 Mar 2022 02:08:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49658 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345131AbiCOGH5 (ORCPT ); Tue, 15 Mar 2022 02:07:57 -0400 Received: from smtpbgsg2.qq.com (smtpbgsg2.qq.com [54.254.200.128]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AE30A49F0A for ; Mon, 14 Mar 2022 23:06:39 -0700 (PDT) X-QQ-mid: bizesmtp72t1647324388tpkqndkg Received: from localhost.localdomain ( [58.240.82.166]) by bizesmtp.qq.com (ESMTP) with id ; Tue, 15 Mar 2022 14:06:22 +0800 (CST) X-QQ-SSF: 01400000002000D0H000B00A0000000 X-QQ-FEAT: LVBOaDZ5gPpMzvCJEg6pDN8IckuawBlvyYOya+4uTTD0CX+0I0yv5amwd3Xz/ P6QtKM695uyr6aXKOF1b5rsu5qVJhNP+Wd/eqw+45c+5xNrJKY0jI7mNQConJb43XrnAGj4 WN3wqgBPK9K1WJ1wJjKoMMercL1dASCb9b8TVs4SzSzGWcc/v63O/arcgSz/0gKXwvsevf2 bXDgiRSMnI6aQ6vIdYyA+hNAtdwm5jCIWFerKV5Y4J2ZrQjjsSGYma6z1Are69ZZfUqUBVD U5uEdKEs6nFoXsRA1VzgsdvZJ2s55aythLhvGWOx9iMxauWNJPuH+zuuaVvroZookLvEFoI UYRi1YnFOGy6AVTygw= X-QQ-GoodBg: 2 From: Meng Tang To: mcgrof@kernel.org, keescook@chromium.org Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, dave@stgolabs.net, nixiaoming@huawei.com, Meng Tang Subject: [PATCH] fs/proc: Introduce list_for_each_table_entry for proc sysctl Date: Tue, 15 Mar 2022 14:06:16 +0800 Message-Id: <20220315060616.31850-1-tangmeng@uniontech.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-QQ-SENDSIZE: 520 Feedback-ID: bizesmtp:uniontech.com:qybgforeign:qybgforeign7 X-QQ-Bgrelay: 1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Use the list_for_each_table_entry macro to optimize the scenario of traverse ctl_table. This make the code neater and easier to understand. Suggested-by: Davidlohr Bueso Signed-off-by: Meng Tang --- fs/proc/proc_sysctl.c | 89 +++++++++++++++++++++++++------------------ 1 file changed, 51 insertions(+), 38 deletions(-) diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 6c87c99f0856..5b14db1f691d 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -19,6 +19,9 @@ #include #include "internal.h" =20 +#define list_for_each_table_entry(entry, table) \ + for ((entry) =3D (table); (entry)->procname; (entry)++) + static const struct dentry_operations proc_sys_dentry_operations; static const struct file_operations proc_sys_file_operations; static const struct inode_operations proc_sys_inode_operations; @@ -215,15 +218,19 @@ static void init_header(struct ctl_table_header *head, INIT_HLIST_HEAD(&head->inodes); if (node) { struct ctl_table *entry; - for (entry =3D table; entry->procname; entry++, node++) + + list_for_each_table_entry(entry, table) { node->header =3D head; + node++; + } } } =20 static void erase_header(struct ctl_table_header *head) { struct ctl_table *entry; - for (entry =3D head->ctl_table; entry->procname; entry++) + + list_for_each_table_entry(entry, head->ctl_table) erase_entry(head, entry); } =20 @@ -248,7 +255,7 @@ static int insert_header(struct ctl_dir *dir, struct ct= l_table_header *header) err =3D insert_links(header); if (err) goto fail_links; - for (entry =3D header->ctl_table; entry->procname; entry++) { + list_for_each_table_entry(entry, header->ctl_table) { err =3D insert_entry(header, entry); if (err) goto fail; @@ -1131,34 +1138,36 @@ static int sysctl_check_table_array(const char *pat= h, struct ctl_table *table) static int sysctl_check_table(const char *path, struct ctl_table *table) { int err =3D 0; - for (; table->procname; table++) { - if (table->child) - err |=3D sysctl_err(path, table, "Not a file"); - - if ((table->proc_handler =3D=3D proc_dostring) || - (table->proc_handler =3D=3D proc_dointvec) || - (table->proc_handler =3D=3D proc_douintvec) || - (table->proc_handler =3D=3D proc_douintvec_minmax) || - (table->proc_handler =3D=3D proc_dointvec_minmax) || - (table->proc_handler =3D=3D proc_dou8vec_minmax) || - (table->proc_handler =3D=3D proc_dointvec_jiffies) || - (table->proc_handler =3D=3D proc_dointvec_userhz_jiffies) || - (table->proc_handler =3D=3D proc_dointvec_ms_jiffies) || - (table->proc_handler =3D=3D proc_doulongvec_minmax) || - (table->proc_handler =3D=3D proc_doulongvec_ms_jiffies_minmax)) { - if (!table->data) - err |=3D sysctl_err(path, table, "No data"); - if (!table->maxlen) - err |=3D sysctl_err(path, table, "No maxlen"); + struct ctl_table *entry; + + list_for_each_table_entry(entry, table) { + if (entry->child) + err |=3D sysctl_err(path, entry, "Not a file"); + + if ((entry->proc_handler =3D=3D proc_dostring) || + (entry->proc_handler =3D=3D proc_dointvec) || + (entry->proc_handler =3D=3D proc_douintvec) || + (entry->proc_handler =3D=3D proc_douintvec_minmax) || + (entry->proc_handler =3D=3D proc_dointvec_minmax) || + (entry->proc_handler =3D=3D proc_dou8vec_minmax) || + (entry->proc_handler =3D=3D proc_dointvec_jiffies) || + (entry->proc_handler =3D=3D proc_dointvec_userhz_jiffies) || + (entry->proc_handler =3D=3D proc_dointvec_ms_jiffies) || + (entry->proc_handler =3D=3D proc_doulongvec_minmax) || + (entry->proc_handler =3D=3D proc_doulongvec_ms_jiffies_minmax)) { + if (!entry->data) + err |=3D sysctl_err(path, entry, "No data"); + if (!entry->maxlen) + err |=3D sysctl_err(path, entry, "No maxlen"); else - err |=3D sysctl_check_table_array(path, table); + err |=3D sysctl_check_table_array(path, entry); } - if (!table->proc_handler) - err |=3D sysctl_err(path, table, "No proc_handler"); + if (!entry->proc_handler) + err |=3D sysctl_err(path, entry, "No proc_handler"); =20 - if ((table->mode & (S_IRUGO|S_IWUGO)) !=3D table->mode) - err |=3D sysctl_err(path, table, "bogus .mode 0%o", - table->mode); + if ((entry->mode & (S_IRUGO|S_IWUGO)) !=3D entry->mode) + err |=3D sysctl_err(path, entry, "bogus .mode 0%o", + entry->mode); } return err; } @@ -1174,7 +1183,7 @@ static struct ctl_table_header *new_links(struct ctl_= dir *dir, struct ctl_table =20 name_bytes =3D 0; nr_entries =3D 0; - for (entry =3D table; entry->procname; entry++) { + list_for_each_table_entry(entry, table) { nr_entries++; name_bytes +=3D strlen(entry->procname) + 1; } @@ -1191,14 +1200,16 @@ static struct ctl_table_header *new_links(struct ct= l_dir *dir, struct ctl_table node =3D (struct ctl_node *)(links + 1); link_table =3D (struct ctl_table *)(node + nr_entries); link_name =3D (char *)&link_table[nr_entries + 1]; + link =3D link_table; =20 - for (link =3D link_table, entry =3D table; entry->procname; link++, entry= ++) { + list_for_each_table_entry(entry, table) { int len =3D strlen(entry->procname) + 1; memcpy(link_name, entry->procname, len); link->procname =3D link_name; link->mode =3D S_IFLNK|S_IRWXUGO; link->data =3D link_root; link_name +=3D len; + link++; } init_header(links, dir->header.root, dir->header.set, node, link_table); links->nreg =3D nr_entries; @@ -1213,7 +1224,7 @@ static bool get_links(struct ctl_dir *dir, struct ctl_table *entry, *link; =20 /* Are there links available for every entry in table? */ - for (entry =3D table; entry->procname; entry++) { + list_for_each_table_entry(entry, table) { const char *procname =3D entry->procname; link =3D find_entry(&head, dir, procname, strlen(procname)); if (!link) @@ -1226,7 +1237,7 @@ static bool get_links(struct ctl_dir *dir, } =20 /* The checks passed. Increase the registration count on the links */ - for (entry =3D table; entry->procname; entry++) { + list_for_each_table_entry(entry, table) { const char *procname =3D entry->procname; link =3D find_entry(&head, dir, procname, strlen(procname)); head->nreg++; @@ -1329,7 +1340,7 @@ struct ctl_table_header *__register_sysctl_table( struct ctl_node *node; int nr_entries =3D 0; =20 - for (entry =3D table; entry->procname; entry++) + list_for_each_table_entry(entry, table) nr_entries++; =20 header =3D kzalloc(sizeof(struct ctl_table_header) + @@ -1456,7 +1467,7 @@ static int count_subheaders(struct ctl_table *table) if (!table || !table->procname) return 1; =20 - for (entry =3D table; entry->procname; entry++) { + list_for_each_table_entry(entry, table) { if (entry->child) nr_subheaders +=3D count_subheaders(entry->child); else @@ -1475,7 +1486,7 @@ static int register_leaf_sysctl_tables(const char *pa= th, char *pos, int nr_dirs =3D 0; int err =3D -ENOMEM; =20 - for (entry =3D table; entry->procname; entry++) { + list_for_each_table_entry(entry, table) { if (entry->child) nr_dirs++; else @@ -1492,7 +1503,9 @@ static int register_leaf_sysctl_tables(const char *pa= th, char *pos, goto out; =20 ctl_table_arg =3D files; - for (new =3D files, entry =3D table; entry->procname; entry++) { + new =3D files; + + list_for_each_table_entry(entry, table) { if (entry->child) continue; *new =3D *entry; @@ -1516,7 +1529,7 @@ static int register_leaf_sysctl_tables(const char *pa= th, char *pos, } =20 /* Recurse into the subdirectories. */ - for (entry =3D table; entry->procname; entry++) { + list_for_each_table_entry(entry, table) { char *child_pos; =20 if (!entry->child) @@ -1670,7 +1683,7 @@ static void put_links(struct ctl_table_header *header) if (IS_ERR(core_parent)) return; =20 - for (entry =3D header->ctl_table; entry->procname; entry++) { + list_for_each_table_entry(entry, header->ctl_table) { struct ctl_table_header *link_head; struct ctl_table *link; const char *name =3D entry->procname; --=20 2.20.1