media: ov5640: change 1080p resolution to 1088p
[linux-2.6.git] / ipc / ipc_sysctl.c
index 79e24e8..00fba2b 100644 (file)
@@ -14,6 +14,9 @@
 #include <linux/nsproxy.h>
 #include <linux/sysctl.h>
 #include <linux/uaccess.h>
+#include <linux/ipc_namespace.h>
+#include <linux/msg.h>
+#include "util.h"
 
 static void *get_ipc(ctl_table *table)
 {
@@ -23,146 +26,212 @@ static void *get_ipc(ctl_table *table)
        return which;
 }
 
-#ifdef CONFIG_PROC_FS
-static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
+#ifdef CONFIG_PROC_SYSCTL
+static int proc_ipc_dointvec(ctl_table *table, int write,
        void __user *buffer, size_t *lenp, loff_t *ppos)
 {
        struct ctl_table ipc_table;
+
+       memcpy(&ipc_table, table, sizeof(ipc_table));
+       ipc_table.data = get_ipc(table);
+
+       return proc_dointvec(&ipc_table, write, buffer, lenp, ppos);
+}
+
+static int proc_ipc_dointvec_minmax(ctl_table *table, int write,
+       void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+       struct ctl_table ipc_table;
+
+       memcpy(&ipc_table, table, sizeof(ipc_table));
+       ipc_table.data = get_ipc(table);
+
+       return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
+}
+
+static int proc_ipc_dointvec_minmax_orphans(ctl_table *table, int write,
+       void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+       struct ipc_namespace *ns = current->nsproxy->ipc_ns;
+       int err = proc_ipc_dointvec_minmax(table, write, buffer, lenp, ppos);
+
+       if (err < 0)
+               return err;
+       if (ns->shm_rmid_forced)
+               shm_destroy_orphaned(ns);
+       return err;
+}
+
+static int proc_ipc_callback_dointvec(ctl_table *table, int write,
+       void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+       struct ctl_table ipc_table;
+       size_t lenp_bef = *lenp;
+       int rc;
+
        memcpy(&ipc_table, table, sizeof(ipc_table));
        ipc_table.data = get_ipc(table);
 
-       return proc_dointvec(&ipc_table, write, filp, buffer, lenp, ppos);
+       rc = proc_dointvec(&ipc_table, write, buffer, lenp, ppos);
+
+       if (write && !rc && lenp_bef == *lenp)
+               /*
+                * Tunable has successfully been changed by hand. Disable its
+                * automatic adjustment. This simply requires unregistering
+                * the notifiers that trigger recalculation.
+                */
+               unregister_ipcns_notifier(current->nsproxy->ipc_ns);
+
+       return rc;
 }
 
 static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
-       struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos)
+       void __user *buffer, size_t *lenp, loff_t *ppos)
 {
        struct ctl_table ipc_table;
        memcpy(&ipc_table, table, sizeof(ipc_table));
        ipc_table.data = get_ipc(table);
 
-       return proc_doulongvec_minmax(&ipc_table, write, filp, buffer,
+       return proc_doulongvec_minmax(&ipc_table, write, buffer,
                                        lenp, ppos);
 }
 
-#else
-#define proc_ipc_doulongvec_minmax NULL
-#define proc_ipc_dointvec         NULL
-#endif
-
-#ifdef CONFIG_SYSCTL_SYSCALL
-/* The generic sysctl ipc data routine. */
-static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen,
-               void __user *oldval, size_t __user *oldlenp,
-               void __user *newval, size_t newlen)
+/*
+ * Routine that is called when the file "auto_msgmni" has successfully been
+ * written.
+ * Two values are allowed:
+ * 0: unregister msgmni's callback routine from the ipc namespace notifier
+ *    chain. This means that msgmni won't be recomputed anymore upon memory
+ *    add/remove or ipc namespace creation/removal.
+ * 1: register back the callback routine.
+ */
+static void ipc_auto_callback(int val)
 {
-       size_t len;
-       void *data;
-
-       /* Get out of I don't have a variable */
-       if (!table->data || !table->maxlen)
-               return -ENOTDIR;
-
-       data = get_ipc(table);
-       if (!data)
-               return -ENOTDIR;
-
-       if (oldval && oldlenp) {
-               if (get_user(len, oldlenp))
-                       return -EFAULT;
-               if (len) {
-                       if (len > table->maxlen)
-                               len = table->maxlen;
-                       if (copy_to_user(oldval, data, len))
-                               return -EFAULT;
-                       if (put_user(len, oldlenp))
-                               return -EFAULT;
-               }
+       if (!val)
+               unregister_ipcns_notifier(current->nsproxy->ipc_ns);
+       else {
+               /*
+                * Re-enable automatic recomputing only if not already
+                * enabled.
+                */
+               recompute_msgmni(current->nsproxy->ipc_ns);
+               cond_register_ipcns_notifier(current->nsproxy->ipc_ns);
        }
+}
 
-       if (newval && newlen) {
-               if (newlen > table->maxlen)
-                       newlen = table->maxlen;
+static int proc_ipcauto_dointvec_minmax(ctl_table *table, int write,
+       void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+       struct ctl_table ipc_table;
+       size_t lenp_bef = *lenp;
+       int oldval;
+       int rc;
 
-               if (copy_from_user(data, newval, newlen))
-                       return -EFAULT;
+       memcpy(&ipc_table, table, sizeof(ipc_table));
+       ipc_table.data = get_ipc(table);
+       oldval = *((int *)(ipc_table.data));
+
+       rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
+
+       if (write && !rc && lenp_bef == *lenp) {
+               int newval = *((int *)(ipc_table.data));
+               /*
+                * The file "auto_msgmni" has correctly been set.
+                * React by (un)registering the corresponding tunable, if the
+                * value has changed.
+                */
+               if (newval != oldval)
+                       ipc_auto_callback(newval);
        }
-       return 1;
+
+       return rc;
 }
+
 #else
-#define sysctl_ipc_data NULL
+#define proc_ipc_doulongvec_minmax NULL
+#define proc_ipc_dointvec         NULL
+#define proc_ipc_dointvec_minmax   NULL
+#define proc_ipc_dointvec_minmax_orphans   NULL
+#define proc_ipc_callback_dointvec NULL
+#define proc_ipcauto_dointvec_minmax NULL
 #endif
 
+static int zero;
+static int one = 1;
+
 static struct ctl_table ipc_kern_table[] = {
        {
-               .ctl_name       = KERN_SHMMAX,
                .procname       = "shmmax",
                .data           = &init_ipc_ns.shm_ctlmax,
                .maxlen         = sizeof (init_ipc_ns.shm_ctlmax),
                .mode           = 0644,
                .proc_handler   = proc_ipc_doulongvec_minmax,
-               .strategy       = sysctl_ipc_data,
        },
        {
-               .ctl_name       = KERN_SHMALL,
                .procname       = "shmall",
                .data           = &init_ipc_ns.shm_ctlall,
                .maxlen         = sizeof (init_ipc_ns.shm_ctlall),
                .mode           = 0644,
                .proc_handler   = proc_ipc_doulongvec_minmax,
-               .strategy       = sysctl_ipc_data,
        },
        {
-               .ctl_name       = KERN_SHMMNI,
                .procname       = "shmmni",
                .data           = &init_ipc_ns.shm_ctlmni,
                .maxlen         = sizeof (init_ipc_ns.shm_ctlmni),
                .mode           = 0644,
                .proc_handler   = proc_ipc_dointvec,
-               .strategy       = sysctl_ipc_data,
        },
        {
-               .ctl_name       = KERN_MSGMAX,
+               .procname       = "shm_rmid_forced",
+               .data           = &init_ipc_ns.shm_rmid_forced,
+               .maxlen         = sizeof(init_ipc_ns.shm_rmid_forced),
+               .mode           = 0644,
+               .proc_handler   = proc_ipc_dointvec_minmax_orphans,
+               .extra1         = &zero,
+               .extra2         = &one,
+       },
+       {
                .procname       = "msgmax",
                .data           = &init_ipc_ns.msg_ctlmax,
                .maxlen         = sizeof (init_ipc_ns.msg_ctlmax),
                .mode           = 0644,
                .proc_handler   = proc_ipc_dointvec,
-               .strategy       = sysctl_ipc_data,
        },
        {
-               .ctl_name       = KERN_MSGMNI,
                .procname       = "msgmni",
                .data           = &init_ipc_ns.msg_ctlmni,
                .maxlen         = sizeof (init_ipc_ns.msg_ctlmni),
                .mode           = 0644,
-               .proc_handler   = proc_ipc_dointvec,
-               .strategy       = sysctl_ipc_data,
+               .proc_handler   = proc_ipc_callback_dointvec,
        },
        {
-               .ctl_name       = KERN_MSGMNB,
                .procname       =  "msgmnb",
                .data           = &init_ipc_ns.msg_ctlmnb,
                .maxlen         = sizeof (init_ipc_ns.msg_ctlmnb),
                .mode           = 0644,
                .proc_handler   = proc_ipc_dointvec,
-               .strategy       = sysctl_ipc_data,
        },
        {
-               .ctl_name       = KERN_SEM,
                .procname       = "sem",
                .data           = &init_ipc_ns.sem_ctls,
                .maxlen         = 4*sizeof (int),
                .mode           = 0644,
                .proc_handler   = proc_ipc_dointvec,
-               .strategy       = sysctl_ipc_data,
+       },
+       {
+               .procname       = "auto_msgmni",
+               .data           = &init_ipc_ns.auto_msgmni,
+               .maxlen         = sizeof(int),
+               .mode           = 0644,
+               .proc_handler   = proc_ipcauto_dointvec_minmax,
+               .extra1         = &zero,
+               .extra2         = &one,
        },
        {}
 };
 
 static struct ctl_table ipc_root_table[] = {
        {
-               .ctl_name       = CTL_KERN,
                .procname       = "kernel",
                .mode           = 0555,
                .child          = ipc_kern_table,