From 734550921e9b7ab924a43aa3d0bd4239dac4fbf1 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 14 Jul 2008 21:22:20 -0400 Subject: [PATCH] [PATCH] beginning of sysctl cleanup - ctl_table_set New object: set of sysctls [currently - root and per-net-ns]. Contains: pointer to parent set, list of tables and "should I see this set?" method (->is_seen(set)). Current lists of tables are subsumed by that; net-ns contains such a beast. ->lookup() for ctl_table_root returns pointer to ctl_table_set instead of that to ->list of that ctl_table_set. [folded compile fixes by rdd for configs without sysctl] Signed-off-by: Al Viro --- include/linux/sysctl.h | 15 ++++++++++++-- include/net/net_namespace.h | 4 +++- kernel/sysctl.c | 41 ++++++++++++++++++++++++++++--------- net/sysctl_net.c | 22 +++++++++----------- 4 files changed, 57 insertions(+), 25 deletions(-) diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 24141b4d1a11..c1e0cf408af9 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -947,6 +947,16 @@ struct ctl_table; struct nsproxy; struct ctl_table_root; +struct ctl_table_set { + struct list_head list; + struct ctl_table_set *parent; + int (*is_seen)(struct ctl_table_set *); +}; + +extern void setup_sysctl_set(struct ctl_table_set *p, + struct ctl_table_set *parent, + int (*is_seen)(struct ctl_table_set *)); + extern struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev); extern struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces, struct ctl_table_header *prev); @@ -1049,8 +1059,8 @@ struct ctl_table struct ctl_table_root { struct list_head root_list; - struct list_head header_list; - struct list_head *(*lookup)(struct ctl_table_root *root, + struct ctl_table_set default_set; + struct ctl_table_set *(*lookup)(struct ctl_table_root *root, struct nsproxy *namespaces); int (*permissions)(struct ctl_table_root *root, struct nsproxy *namespaces, struct ctl_table *table); @@ -1066,6 +1076,7 @@ struct ctl_table_header struct completion *unregistering; struct ctl_table *ctl_table_arg; struct ctl_table_root *root; + struct ctl_table_set *set; }; /* struct ctl_path describes where in the hierarchy a table is added */ diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 3855620b78a9..a8eb43cf0c7e 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -38,7 +38,9 @@ struct net { struct proc_dir_entry *proc_net; struct proc_dir_entry *proc_net_stat; - struct list_head sysctl_table_headers; +#ifdef CONFIG_SYSCTL + struct ctl_table_set sysctls; +#endif struct net_device *loopback_dev; /* The loopback */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 35a50db9b6ce..8ee4a0619fbb 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -160,12 +160,13 @@ static struct ctl_table root_table[]; static struct ctl_table_root sysctl_table_root; static struct ctl_table_header root_table_header = { .ctl_table = root_table, - .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.header_list), + .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list), .root = &sysctl_table_root, + .set = &sysctl_table_root.default_set, }; static struct ctl_table_root sysctl_table_root = { .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list), - .header_list = LIST_HEAD_INIT(root_table_header.ctl_entry), + .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry), }; static struct ctl_table kern_table[]; @@ -1403,14 +1404,20 @@ void sysctl_head_finish(struct ctl_table_header *head) spin_unlock(&sysctl_lock); } +static struct ctl_table_set * +lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces) +{ + struct ctl_table_set *set = &root->default_set; + if (root->lookup) + set = root->lookup(root, namespaces); + return set; +} + static struct list_head * lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces) { - struct list_head *header_list; - header_list = &root->header_list; - if (root->lookup) - header_list = root->lookup(root, namespaces); - return header_list; + struct ctl_table_set *set = lookup_header_set(root, namespaces); + return &set->list; } struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces, @@ -1720,7 +1727,6 @@ struct ctl_table_header *__register_sysctl_paths( struct nsproxy *namespaces, const struct ctl_path *path, struct ctl_table *table) { - struct list_head *header_list; struct ctl_table_header *header; struct ctl_table *new, **prevp; unsigned int n, npath; @@ -1772,8 +1778,8 @@ struct ctl_table_header *__register_sysctl_paths( } #endif spin_lock(&sysctl_lock); - header_list = lookup_header_list(root, namespaces); - list_add_tail(&header->ctl_entry, header_list); + header->set = lookup_header_set(root, namespaces); + list_add_tail(&header->ctl_entry, &header->set->list); spin_unlock(&sysctl_lock); return header; @@ -1832,6 +1838,15 @@ void unregister_sysctl_table(struct ctl_table_header * header) kfree(header); } +void setup_sysctl_set(struct ctl_table_set *p, + struct ctl_table_set *parent, + int (*is_seen)(struct ctl_table_set *)) +{ + INIT_LIST_HEAD(&p->list); + p->parent = parent ? parent : &sysctl_table_root.default_set; + p->is_seen = is_seen; +} + #else /* !CONFIG_SYSCTL */ struct ctl_table_header *register_sysctl_table(struct ctl_table * table) { @@ -1848,6 +1863,12 @@ void unregister_sysctl_table(struct ctl_table_header * table) { } +void setup_sysctl_set(struct ctl_table_set *p, + struct ctl_table_set *parent, + int (*is_seen)(struct ctl_table_set *)) +{ +} + #endif /* CONFIG_SYSCTL */ /* diff --git a/net/sysctl_net.c b/net/sysctl_net.c index 63ada437fc2f..cefbc367d8be 100644 --- a/net/sysctl_net.c +++ b/net/sysctl_net.c @@ -29,10 +29,15 @@ #include #endif -static struct list_head * +static struct ctl_table_set * net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces) { - return &namespaces->net_ns->sysctl_table_headers; + return &namespaces->net_ns->sysctls; +} + +static int is_seen(struct ctl_table_set *set) +{ + return ¤t->nsproxy->net_ns->sysctls == set; } /* Return standard mode bits for table entry. */ @@ -53,13 +58,6 @@ static struct ctl_table_root net_sysctl_root = { .permissions = net_ctl_permissions, }; -static LIST_HEAD(net_sysctl_ro_tables); -static struct list_head *net_ctl_ro_header_lookup(struct ctl_table_root *root, - struct nsproxy *namespaces) -{ - return &net_sysctl_ro_tables; -} - static int net_ctl_ro_header_perms(struct ctl_table_root *root, struct nsproxy *namespaces, struct ctl_table *table) { @@ -70,19 +68,18 @@ static int net_ctl_ro_header_perms(struct ctl_table_root *root, } static struct ctl_table_root net_sysctl_ro_root = { - .lookup = net_ctl_ro_header_lookup, .permissions = net_ctl_ro_header_perms, }; static int sysctl_net_init(struct net *net) { - INIT_LIST_HEAD(&net->sysctl_table_headers); + setup_sysctl_set(&net->sysctls, NULL, is_seen); return 0; } static void sysctl_net_exit(struct net *net) { - WARN_ON(!list_empty(&net->sysctl_table_headers)); + WARN_ON(!list_empty(&net->sysctls.list)); return; } @@ -98,6 +95,7 @@ static __init int sysctl_init(void) if (ret) goto out; register_sysctl_root(&net_sysctl_root); + setup_sysctl_set(&net_sysctl_ro_root.default_set, NULL, NULL); register_sysctl_root(&net_sysctl_ro_root); out: return ret;