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authorEric W. Biederman <ebiederm@xmission.com>2007-02-14 00:34:12 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-02-14 08:10:00 -0800
commit77b14db502cb85a031fe8fde6c85d52f3e0acb63 (patch)
tree4201f6a4dfe1062d1dc00659c403d630401b87cc /kernel/sysctl.c
parent1ff007eb8e8c7c44e9a384a67d0fdd0fd06ba811 (diff)
downloadop-kernel-dev-77b14db502cb85a031fe8fde6c85d52f3e0acb63.zip
op-kernel-dev-77b14db502cb85a031fe8fde6c85d52f3e0acb63.tar.gz
[PATCH] sysctl: reimplement the sysctl proc support
With this change the sysctl inodes can be cached and nothing needs to be done when removing a sysctl table. For a cost of 2K code we will save about 4K of static tables (when we remove de from ctl_table) and 70K in proc_dir_entries that we will not allocate, or about half that on a 32bit arch. The speed feels about the same, even though we can now cache the sysctl dentries :( We get the core advantage that we don't need to have a 1 to 1 mapping between ctl table entries and proc files. Making it possible to have /proc/sys vary depending on the namespace you are in. The currently merged namespaces don't have an issue here but the network namespace under /proc/sys/net needs to have different directories depending on which network adapters are visible. By simply being a cache different directories being visible depending on who you are is trivial to implement. [akpm@osdl.org: fix uninitialised var] [akpm@osdl.org: fix ARM build] [bunk@stusta.de: make things static] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/sysctl.c')
-rw-r--r--kernel/sysctl.c182
1 files changed, 0 insertions, 182 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 6bbac5c..b3ee791 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -159,26 +159,6 @@ int sysctl_legacy_va_layout;
#endif
-/* /proc declarations: */
-
-#ifdef CONFIG_PROC_SYSCTL
-
-static ssize_t proc_readsys(struct file *, char __user *, size_t, loff_t *);
-static ssize_t proc_writesys(struct file *, const char __user *, size_t, loff_t *);
-static int proc_opensys(struct inode *, struct file *);
-
-const struct file_operations proc_sys_file_operations = {
- .open = proc_opensys,
- .read = proc_readsys,
- .write = proc_writesys,
-};
-
-extern struct proc_dir_entry *proc_sys_root;
-
-static void register_proc_table(ctl_table *, struct proc_dir_entry *, void *);
-static void unregister_proc_table(ctl_table *, struct proc_dir_entry *);
-#endif
-
/* The default sysctl tables: */
static ctl_table root_table[] = {
@@ -1106,13 +1086,6 @@ struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
return NULL;
}
-void __init sysctl_init(void)
-{
-#ifdef CONFIG_PROC_SYSCTL
- register_proc_table(root_table, proc_sys_root, &root_table_header);
-#endif
-}
-
#ifdef CONFIG_SYSCTL_SYSCALL
int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen)
@@ -1348,9 +1321,6 @@ struct ctl_table_header *register_sysctl_table(ctl_table * table)
spin_lock(&sysctl_lock);
list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
spin_unlock(&sysctl_lock);
-#ifdef CONFIG_PROC_SYSCTL
- register_proc_table(table, proc_sys_root, tmp);
-#endif
return tmp;
}
@@ -1366,9 +1336,6 @@ void unregister_sysctl_table(struct ctl_table_header * header)
might_sleep();
spin_lock(&sysctl_lock);
start_unregistering(header);
-#ifdef CONFIG_PROC_SYSCTL
- unregister_proc_table(header->ctl_table, proc_sys_root);
-#endif
spin_unlock(&sysctl_lock);
kfree(header);
}
@@ -1392,155 +1359,6 @@ void unregister_sysctl_table(struct ctl_table_header * table)
#ifdef CONFIG_PROC_SYSCTL
-/* Scan the sysctl entries in table and add them all into /proc */
-static void register_proc_table(ctl_table * table, struct proc_dir_entry *root, void *set)
-{
- struct proc_dir_entry *de;
- int len;
- mode_t mode;
-
- for (; table->ctl_name || table->procname; table++) {
- /* Can't do anything without a proc name. */
- if (!table->procname)
- continue;
- /* Maybe we can't do anything with it... */
- if (!table->proc_handler && !table->child) {
- printk(KERN_WARNING "SYSCTL: Can't register %s\n",
- table->procname);
- continue;
- }
-
- len = strlen(table->procname);
- mode = table->mode;
-
- de = NULL;
- if (table->proc_handler)
- mode |= S_IFREG;
- else {
- mode |= S_IFDIR;
- for (de = root->subdir; de; de = de->next) {
- if (proc_match(len, table->procname, de))
- break;
- }
- /* If the subdir exists already, de is non-NULL */
- }
-
- if (!de) {
- de = create_proc_entry(table->procname, mode, root);
- if (!de)
- continue;
- de->set = set;
- de->data = (void *) table;
- if (table->proc_handler)
- de->proc_fops = &proc_sys_file_operations;
- }
- table->de = de;
- if (de->mode & S_IFDIR)
- register_proc_table(table->child, de, set);
- }
-}
-
-/*
- * Unregister a /proc sysctl table and any subdirectories.
- */
-static void unregister_proc_table(ctl_table * table, struct proc_dir_entry *root)
-{
- struct proc_dir_entry *de;
- for (; table->ctl_name || table->procname; table++) {
- if (!(de = table->de))
- continue;
- if (de->mode & S_IFDIR) {
- if (!table->child) {
- printk (KERN_ALERT "Help - malformed sysctl tree on free\n");
- continue;
- }
- unregister_proc_table(table->child, de);
-
- /* Don't unregister directories which still have entries.. */
- if (de->subdir)
- continue;
- }
-
- /*
- * In any case, mark the entry as goner; we'll keep it
- * around if it's busy, but we'll know to do nothing with
- * its fields. We are under sysctl_lock here.
- */
- de->data = NULL;
-
- /* Don't unregister proc entries that are still being used.. */
- if (atomic_read(&de->count))
- continue;
-
- table->de = NULL;
- remove_proc_entry(table->procname, root);
- }
-}
-
-static ssize_t do_rw_proc(int write, struct file * file, char __user * buf,
- size_t count, loff_t *ppos)
-{
- int op;
- struct proc_dir_entry *de = PDE(file->f_path.dentry->d_inode);
- struct ctl_table *table;
- size_t res;
- ssize_t error = -ENOTDIR;
-
- spin_lock(&sysctl_lock);
- if (de && de->data && use_table(de->set)) {
- /*
- * at that point we know that sysctl was not unregistered
- * and won't be until we finish
- */
- spin_unlock(&sysctl_lock);
- table = (struct ctl_table *) de->data;
- if (!table || !table->proc_handler)
- goto out;
- error = -EPERM;
- op = (write ? 002 : 004);
- if (sysctl_perm(table, op))
- goto out;
-
- /* careful: calling conventions are nasty here */
- res = count;
- error = (*table->proc_handler)(table, write, file,
- buf, &res, ppos);
- if (!error)
- error = res;
- out:
- spin_lock(&sysctl_lock);
- unuse_table(de->set);
- }
- spin_unlock(&sysctl_lock);
- return error;
-}
-
-static int proc_opensys(struct inode *inode, struct file *file)
-{
- if (file->f_mode & FMODE_WRITE) {
- /*
- * sysctl entries that are not writable,
- * are _NOT_ writable, capabilities or not.
- */
- if (!(inode->i_mode & S_IWUSR))
- return -EPERM;
- }
-
- return 0;
-}
-
-static ssize_t proc_readsys(struct file * file, char __user * buf,
- size_t count, loff_t *ppos)
-{
- return do_rw_proc(0, file, buf, count, ppos);
-}
-
-static ssize_t proc_writesys(struct file * file, const char __user * buf,
- size_t count, loff_t *ppos)
-{
- return do_rw_proc(1, file, (char __user *) buf, count, ppos);
-}
-
static int _proc_do_string(void* data, int maxlen, int write,
struct file *filp, void __user *buffer,
size_t *lenp, loff_t *ppos)
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