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<dave@xxxxxxxxxxxx>
Signed-off-by: Meng Tang <tangmeng@xxxxxxxxxxxxx>
---
fs/proc/proc_sysctl.c | 81 +++++++++++++++++++++++++------------------
1 file changed, 47 insertions(+), 34 deletions(-)
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index fea2561d773b..4f31c68e8ed9 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -13,6 +13,9 @@
#include <linux/module.h>
#include "internal.h"
+#define list_for_each_table_entry(entry, table) \
+ for ((entry) = (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;
@@ -170,15 +173,19 @@ static void init_header(struct ctl_table_header *head,
head->node = node;
if (node) {
struct ctl_table *entry;
- for (entry = table; entry->procname; entry++, node++)
+
+ list_for_each_table_entry(entry, table) {
node->header = head;
+ node++;
+ }
}
}
static void erase_header(struct ctl_table_header *head)
{
struct ctl_table *entry;
- for (entry = head->ctl_table; entry->procname; entry++)
+
+ list_for_each_table_entry(entry, head->ctl_table)
erase_entry(head, entry);
}
@@ -192,7 +199,7 @@ static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header)
err = insert_links(header);
if (err)
goto fail_links;
- for (entry = header->ctl_table; entry->procname; entry++) {
+ list_for_each_table_entry(entry, header->ctl_table) {
err = insert_entry(header, entry);
if (err)
goto fail;
@@ -989,30 +996,32 @@ static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...)
static int sysctl_check_table(const char *path, struct ctl_table *table)
{
+ struct ctl_table *entry;
int err = 0;
- for (; table->procname; table++) {
- if (table->child)
- err = sysctl_err(path, table, "Not a file");
-
- if ((table->proc_handler == proc_dostring) ||
- (table->proc_handler == proc_dointvec) ||
- (table->proc_handler == proc_dointvec_minmax) ||
- (table->proc_handler == proc_dointvec_jiffies) ||
- (table->proc_handler == proc_dointvec_userhz_jiffies) ||
- (table->proc_handler == proc_dointvec_ms_jiffies) ||
- (table->proc_handler == proc_doulongvec_minmax) ||
- (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) {
- if (!table->data)
- err = sysctl_err(path, table, "No data");
- if (!table->maxlen)
- err = sysctl_err(path, table, "No maxlen");
+
+ list_for_each_table_entry(entry, table) {
+ if (entry->child)
+ err = sysctl_err(path, entry, "Not a file");
+
+ if ((entry->proc_handler == proc_dostring) ||
+ (entry->proc_handler == proc_dointvec) ||
+ (entry->proc_handler == proc_dointvec_minmax) ||
+ (entry->proc_handler == proc_dointvec_jiffies) ||
+ (entry->proc_handler == proc_dointvec_userhz_jiffies) ||
+ (entry->proc_handler == proc_dointvec_ms_jiffies) ||
+ (entry->proc_handler == proc_doulongvec_minmax) ||
+ (entry->proc_handler == proc_doulongvec_ms_jiffies_minmax)) {
+ if (!entry->data)
+ err = sysctl_err(path, entry, "No data");
+ if (!entry->maxlen)
+ err = sysctl_err(path, entry, "No maxlen");
}
- if (!table->proc_handler)
- err = sysctl_err(path, table, "No proc_handler");
+ if (!entry->proc_handler)
+ err = sysctl_err(path, entry, "No proc_handler");
- if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode)
- err = sysctl_err(path, table, "bogus .mode 0%o",
- table->mode);
+ if ((entry->mode & (S_IRUGO|S_IWUGO)) != entry->mode)
+ err = sysctl_err(path, entry, "bogus .mode 0%o",
+ entry->mode);
}
return err;
}
@@ -1028,7 +1037,7 @@ static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table
name_bytes = 0;
nr_entries = 0;
- for (entry = table; entry->procname; entry++) {
+ list_for_each_table_entry(entry, table) {
nr_entries++;
name_bytes += strlen(entry->procname) + 1;
}
@@ -1045,14 +1054,16 @@ static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table
node = (struct ctl_node *)(links + 1);
link_table = (struct ctl_table *)(node + nr_entries);
link_name = (char *)&link_table[nr_entries + 1];
+ link = link_table;
- for (link = link_table, entry = table; entry->procname; link++, entry++) {
+ list_for_each_table_entry(entry, table) {
int len = strlen(entry->procname) + 1;
memcpy(link_name, entry->procname, len);
link->procname = link_name;
link->mode = S_IFLNK|S_IRWXUGO;
link->data = link_root;
link_name += len;
+ link++;
}
init_header(links, dir->header.root, dir->header.set, node, link_table);
links->nreg = nr_entries;
@@ -1067,7 +1078,7 @@ static bool get_links(struct ctl_dir *dir,
struct ctl_table *entry, *link;
/* Are there links available for every entry in table? */
- for (entry = table; entry->procname; entry++) {
+ list_for_each_table_entry(entry, table) {
const char *procname = entry->procname;
link = find_entry(&head, dir, procname, strlen(procname));
if (!link)
@@ -1080,7 +1091,7 @@ static bool get_links(struct ctl_dir *dir,
}
/* The checks passed. Increase the registration count on the links */
- for (entry = table; entry->procname; entry++) {
+ list_for_each_table_entry(entry, table) {
const char *procname = entry->procname;
link = find_entry(&head, dir, procname, strlen(procname));
head->nreg++;
@@ -1183,7 +1194,7 @@ struct ctl_table_header *__register_sysctl_table(
struct ctl_node *node;
int nr_entries = 0;
- for (entry = table; entry->procname; entry++)
+ list_for_each_table_entry(entry, table)
nr_entries++;
header = kzalloc(sizeof(struct ctl_table_header) +
@@ -1278,7 +1289,7 @@ static int count_subheaders(struct ctl_table *table)
if (!table || !table->procname)
return 1;
- for (entry = table; entry->procname; entry++) {
+ list_for_each_table_entry(entry, table) {
if (entry->child)
nr_subheaders += count_subheaders(entry->child);
else
@@ -1297,7 +1308,7 @@ static int register_leaf_sysctl_tables(const char *path, char *pos,
int nr_dirs = 0;
int err = -ENOMEM;
- for (entry = table; entry->procname; entry++) {
+ list_for_each_table_entry(entry, table) {
if (entry->child)
nr_dirs++;
else
@@ -1314,7 +1325,9 @@ static int register_leaf_sysctl_tables(const char *path, char *pos,
goto out;
ctl_table_arg = files;
- for (new = files, entry = table; entry->procname; entry++) {
+ new = files;
+
+ list_for_each_table_entry(entry, table) {
if (entry->child)
continue;
*new = *entry;
@@ -1338,7 +1351,7 @@ static int register_leaf_sysctl_tables(const char *path, char *pos,
}
/* Recurse into the subdirectories. */
- for (entry = table; entry->procname; entry++) {
+ list_for_each_table_entry(entry, table) {
char *child_pos;
if (!entry->child)
@@ -1483,7 +1496,7 @@ static void put_links(struct ctl_table_header *header)
if (IS_ERR(core_parent))
return;
- for (entry = 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 = entry->procname;
--
2.20.1
