Dynamic memory allocation is needed to modify .data and specify the
per namespace parameter. The new sysctl API is allowed to get rid of
the need for such modification.
Signed-off-by: Alexey Gladkov <legion@xxxxxxxxxx>
---
include/linux/ipc_namespace.h | 17 -----
ipc/mq_sysctl.c | 138 +++++++++++++++++++---------------
ipc/mqueue.c | 5 --
ipc/namespace.c | 6 --
4 files changed, 79 insertions(+), 87 deletions(-)
diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index 51c2c247c447..d20753093a2c 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -174,21 +174,4 @@ static inline void put_ipc_ns(struct ipc_namespace *ns)
}
#endif
-#ifdef CONFIG_POSIX_MQUEUE_SYSCTL
-
-void retire_mq_sysctls(struct ipc_namespace *ns);
-bool setup_mq_sysctls(struct ipc_namespace *ns);
-
-#else /* CONFIG_POSIX_MQUEUE_SYSCTL */
-
-static inline void retire_mq_sysctls(struct ipc_namespace *ns)
-{
-}
-
-static inline bool setup_mq_sysctls(struct ipc_namespace *ns)
-{
- return true;
-}
-
-#endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
#endif
diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c
index fbf6a8b93a26..08ff7dfb721c 100644
--- a/ipc/mq_sysctl.c
+++ b/ipc/mq_sysctl.c
@@ -13,6 +13,45 @@
#include <linux/capability.h>
#include <linux/slab.h>
+static inline void *data_from_ns(struct ctl_context *ctx, struct ctl_table *table);
+
+static int mq_sys_open(struct ctl_context *ctx, struct inode *inode, struct file *file)
+{
+ ctx->ctl_data = current->nsproxy->ipc_ns;
+ return 0;
+}
+
+static ssize_t mq_sys_read(struct ctl_context *ctx, struct file *file,
+ char *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table table = *ctx->table;
+ table.data = data_from_ns(ctx, ctx->table);
+ return table.proc_handler(&table, 0, buffer, lenp, ppos);
+}
+
+static ssize_t mq_sys_write(struct ctl_context *ctx, struct file *file,
+ char *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table table = *ctx->table;
+ table.data = data_from_ns(ctx, ctx->table);
+ return table.proc_handler(&table, 1, buffer, lenp, ppos);
+}
+
+static struct ctl_fops mq_sys_fops = {
+ .open = mq_sys_open,
+ .read = mq_sys_read,
+ .write = mq_sys_write,
+};
+
+enum {
+ MQ_SYSCTL_QUEUES_MAX,
+ MQ_SYSCTL_MSG_MAX,
+ MQ_SYSCTL_MSGSIZE_MAX,
+ MQ_SYSCTL_MSG_DEFAULT,
+ MQ_SYSCTL_MSGSIZE_DEFAULT,
+ MQ_SYSCTL_COUNTS
+};
+
static int msg_max_limit_min = MIN_MSGMAX;
static int msg_max_limit_max = HARD_MSGMAX;
@@ -20,14 +59,15 @@ static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
static struct ctl_table mq_sysctls[] = {
- {
+ [MQ_SYSCTL_QUEUES_MAX] = {
.procname = "queues_max",
.data = &init_ipc_ns.mq_queues_max,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
+ .ctl_fops = &mq_sys_fops,
},
- {
+ [MQ_SYSCTL_MSG_MAX] = {
.procname = "msg_max",
.data = &init_ipc_ns.mq_msg_max,
.maxlen = sizeof(int),
@@ -35,8 +75,9 @@ static struct ctl_table mq_sysctls[] = {
.proc_handler = proc_dointvec_minmax,
.extra1 = &msg_max_limit_min,
.extra2 = &msg_max_limit_max,
+ .ctl_fops = &mq_sys_fops,
},
- {
+ [MQ_SYSCTL_MSGSIZE_MAX] = {
.procname = "msgsize_max",
.data = &init_ipc_ns.mq_msgsize_max,
.maxlen = sizeof(int),
@@ -44,8 +85,9 @@ static struct ctl_table mq_sysctls[] = {
.proc_handler = proc_dointvec_minmax,
.extra1 = &msg_maxsize_limit_min,
.extra2 = &msg_maxsize_limit_max,
+ .ctl_fops = &mq_sys_fops,
},
- {
+ [MQ_SYSCTL_MSG_DEFAULT] = {
.procname = "msg_default",
.data = &init_ipc_ns.mq_msg_default,
.maxlen = sizeof(int),
@@ -53,8 +95,9 @@ static struct ctl_table mq_sysctls[] = {
.proc_handler = proc_dointvec_minmax,
.extra1 = &msg_max_limit_min,
.extra2 = &msg_max_limit_max,
+ .ctl_fops = &mq_sys_fops,
},
- {
+ [MQ_SYSCTL_MSGSIZE_DEFAULT] = {
.procname = "msgsize_default",
.data = &init_ipc_ns.mq_msgsize_default,
.maxlen = sizeof(int),
@@ -62,70 +105,47 @@ static struct ctl_table mq_sysctls[] = {
.proc_handler = proc_dointvec_minmax,
.extra1 = &msg_maxsize_limit_min,
.extra2 = &msg_maxsize_limit_max,
+ .ctl_fops = &mq_sys_fops,
},
{}
};
-static struct ctl_table_set *set_lookup(struct ctl_table_root *root)
+static inline void *data_from_ns(struct ctl_context *ctx, struct ctl_table *table)
{
- return ¤t->nsproxy->ipc_ns->mq_set;
+ struct ipc_namespace *ns = ctx->ctl_data;
+
+ switch (ctx->table - mq_sysctls) {
+ case MQ_SYSCTL_QUEUES_MAX: return &ns->mq_queues_max;
+ case MQ_SYSCTL_MSG_MAX: return &ns->mq_msg_max;
+ case MQ_SYSCTL_MSGSIZE_MAX: return &ns->mq_msgsize_max;
+ case MQ_SYSCTL_MSG_DEFAULT: return &ns->mq_msg_default;
+ case MQ_SYSCTL_MSGSIZE_DEFAULT: return &ns->mq_msgsize_default;
+ }
+ return NULL;
}
-static int set_is_seen(struct ctl_table_set *set)
-{
- return ¤t->nsproxy->ipc_ns->mq_set == set;
-}
+static struct ctl_table mq_sysctl_dir[] = {
+ {
+ .procname = "mqueue",
+ .mode = 0555,
+ .child = mq_sysctls,
+ },
+ {}
+};
-static struct ctl_table_root set_root = {
- .lookup = set_lookup,
+static struct ctl_table mq_sysctl_root[] = {
+ {
+ .procname = "fs",
+ .mode = 0555,
+ .child = mq_sysctl_dir,
+ },
+ {}
};
-bool setup_mq_sysctls(struct ipc_namespace *ns)
+static int __init mq_sysctl_init(void)
{
- struct ctl_table *tbl;
-
- setup_sysctl_set(&ns->mq_set, &set_root, set_is_seen);
-
- tbl = kmemdup(mq_sysctls, sizeof(mq_sysctls), GFP_KERNEL);
- if (tbl) {
- int i;
-
- for (i = 0; i < ARRAY_SIZE(mq_sysctls); i++) {
- if (tbl[i].data == &init_ipc_ns.mq_queues_max)
- tbl[i].data = &ns->mq_queues_max;
-
- else if (tbl[i].data == &init_ipc_ns.mq_msg_max)
- tbl[i].data = &ns->mq_msg_max;
-
- else if (tbl[i].data == &init_ipc_ns.mq_msgsize_max)
- tbl[i].data = &ns->mq_msgsize_max;
-
- else if (tbl[i].data == &init_ipc_ns.mq_msg_default)
- tbl[i].data = &ns->mq_msg_default;
-
- else if (tbl[i].data == &init_ipc_ns.mq_msgsize_default)
- tbl[i].data = &ns->mq_msgsize_default;
- else
- tbl[i].data = NULL;
- }
-
- ns->mq_sysctls = __register_sysctl_table(&ns->mq_set, "fs/mqueue", tbl);
- }
- if (!ns->mq_sysctls) {
- kfree(tbl);
- retire_sysctl_set(&ns->mq_set);
- return false;
- }
-
- return true;
+ register_sysctl_table(mq_sysctl_root);
+ return 0;
}
-void retire_mq_sysctls(struct ipc_namespace *ns)
-{
- struct ctl_table *tbl;
-
- tbl = ns->mq_sysctls->ctl_table_arg;
- unregister_sysctl_table(ns->mq_sysctls);
- retire_sysctl_set(&ns->mq_set);
- kfree(tbl);
-}
+device_initcall(mq_sysctl_init);
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index c0f24cc9f619..ffb79a24d70b 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -1711,11 +1711,6 @@ static int __init init_mqueue_fs(void)
if (mqueue_inode_cachep == NULL)
return -ENOMEM;
- if (!setup_mq_sysctls(&init_ipc_ns)) {
- pr_warn("sysctl registration failed\n");
- return -ENOMEM;
- }
-
error = register_filesystem(&mqueue_fs_type);
if (error)
goto out_sysctl;
diff --git a/ipc/namespace.c b/ipc/namespace.c
index f760243ca685..ae83f0f2651b 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -59,10 +59,6 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
if (err)
goto fail_put;
- err = -ENOMEM;
- if (!setup_mq_sysctls(ns))
- goto fail_put;
-
sem_init_ns(ns);
msg_init_ns(ns);
shm_init_ns(ns);
@@ -129,8 +125,6 @@ static void free_ipc_ns(struct ipc_namespace *ns)
msg_exit_ns(ns);
shm_exit_ns(ns);
- retire_mq_sysctls(ns);
-
dec_ipc_namespaces(ns->ucounts);
put_user_ns(ns->user_ns);
ns_free_inum(&ns->ns);
--
2.33.3
