*
* Virtual Server: Context Support
*
- * Copyright (C) 2003-2004 Herbert Pötzl
+ * Copyright (C) 2003-2005 Herbert Pötzl
*
* V0.01 context helper
* V0.02 vx_ctx_kill syscall command
* V0.06 task_xid and info commands
* V0.07 context flags and caps
* V0.08 switch to RCU based hash
+ * V0.09 revert to non RCU for now
+ * V0.10 and back to working RCU hash
+ * V0.11 and back to locking again
*
*/
#include <linux/config.h>
#include <linux/slab.h>
-#include <linux/vserver.h>
+#include <linux/types.h>
+#include <linux/namespace.h>
+
+#include <linux/sched.h>
+#include <linux/vserver/network.h>
#include <linux/vserver/legacy.h>
-#include <linux/vs_base.h>
+#include <linux/vserver/limit.h>
+#include <linux/vserver/debug.h>
+
#include <linux/vs_context.h>
-#include <linux/kernel_stat.h>
-#include <linux/namespace.h>
-#include <linux/rcupdate.h>
+#include <linux/vserver/context_cmd.h>
+#include <linux/err.h>
#include <asm/errno.h>
+#include "cvirt_init.h"
+#include "limit_init.h"
+#include "sched_init.h"
+
/* __alloc_vx_info()
memset (new, 0, sizeof(struct vx_info));
new->vx_id = xid;
- INIT_RCU_HEAD(&new->vx_rcu);
+ // INIT_RCU_HEAD(&new->vx_rcu);
INIT_HLIST_NODE(&new->vx_hlist);
- atomic_set(&new->vx_refcnt, 0);
atomic_set(&new->vx_usecnt, 0);
+ atomic_set(&new->vx_tasks, 0);
new->vx_parent = NULL;
new->vx_state = 0;
new->vx_lock = SPIN_LOCK_UNLOCKED;
vxdprintk(VXD_CBIT(xid, 0),
"alloc_vx_info(%d) = %p", xid, new);
+ vxh_alloc_vx_info(new);
return new;
}
{
vxdprintk(VXD_CBIT(xid, 0),
"dealloc_vx_info(%p)", vxi);
+ vxh_dealloc_vx_info(vxi);
vxi->vx_hlist.next = LIST_POISON1;
vxi->vx_id = -1;
vx_info_exit_cvirt(&vxi->cvirt);
vx_info_exit_cacct(&vxi->cacct);
-
- BUG_ON(atomic_read(&vxi->vx_usecnt));
- BUG_ON(atomic_read(&vxi->vx_refcnt));
-
- BUG_ON(vx_info_state(vxi, VXS_HASHED));
- // BUG_ON(!vx_state(vxi, VXS_DEFUNCT));
-
vxi->vx_state |= VXS_RELEASED;
kfree(vxi);
}
-static inline int __free_vx_info(struct vx_info *vxi)
+void __shutdown_vx_info(struct vx_info *vxi)
{
- int usecnt, refcnt;
-
- BUG_ON(!vxi);
-
- usecnt = atomic_read(&vxi->vx_usecnt);
- BUG_ON(usecnt < 0);
-
- refcnt = atomic_read(&vxi->vx_refcnt);
- BUG_ON(refcnt < 0);
-
- if (!usecnt)
- __dealloc_vx_info(vxi);
- return usecnt;
-}
-
-#if 0
+ struct namespace *namespace;
+ struct fs_struct *fs;
-static void __rcu_free_vx_info(struct rcu_head *head)
-{
- struct vx_info *vxi = container_of(head, struct vx_info, vx_rcu);
+ might_sleep();
- BUG_ON(!head);
- vxdprintk(VXD_CBIT(xid, 3),
- "rcu_free_vx_info(%p): uc=%d", vxi,
- atomic_read(&vxi->vx_usecnt));
+ namespace = xchg(&vxi->vx_namespace, NULL);
+ if (namespace)
+ put_namespace(namespace);
- __free_vx_info(vxi);
+ fs = xchg(&vxi->vx_fs, NULL);
+ if (fs)
+ put_fs_struct(fs);
}
-#endif
+/* exported stuff */
void free_vx_info(struct vx_info *vxi)
{
- struct namespace *namespace;
- struct fs_struct *fs;
-
/* context shutdown is mandatory */
// BUG_ON(vxi->vx_state != VXS_SHUTDOWN);
- namespace = xchg(&vxi->vx_namespace, NULL);
- fs = xchg(&vxi->vx_fs, NULL);
+ BUG_ON(atomic_read(&vxi->vx_usecnt));
+ BUG_ON(atomic_read(&vxi->vx_tasks));
- if (namespace)
- put_namespace(namespace);
- if (fs)
- put_fs_struct(fs);
+ BUG_ON(vx_info_state(vxi, VXS_HASHED));
+ // BUG_ON(!vx_state(vxi, VXS_DEFUNCT));
- BUG_ON(__free_vx_info(vxi));
- // call_rcu(&i->vx_rcu, __rcu_free_vx_info);
+ BUG_ON(vxi->vx_namespace);
+ BUG_ON(vxi->vx_fs);
+
+ __dealloc_vx_info(vxi);
}
{
struct hlist_head *head;
+ vxd_assert_lock(&vx_info_hash_lock);
vxdprintk(VXD_CBIT(xid, 4),
"__hash_vx_info: %p[#%d]", vxi, vxi->vx_id);
+ vxh_hash_vx_info(vxi);
+
+ /* context must not be hashed */
+ BUG_ON(vxi->vx_state & VXS_HASHED);
+
get_vx_info(vxi);
vxi->vx_state |= VXS_HASHED;
head = &vx_info_hash[__hashval(vxi->vx_id)];
- hlist_add_head_rcu(&vxi->vx_hlist, head);
+ hlist_add_head(&vxi->vx_hlist, head);
}
/* __unhash_vx_info()
static inline void __unhash_vx_info(struct vx_info *vxi)
{
+ vxd_assert_lock(&vx_info_hash_lock);
vxdprintk(VXD_CBIT(xid, 4),
"__unhash_vx_info: %p[#%d]", vxi, vxi->vx_id);
+ vxh_unhash_vx_info(vxi);
+
+ /* maybe warn on that? */
+ if (!(vxi->vx_state & VXS_HASHED))
+ return;
+
vxi->vx_state &= ~VXS_HASHED;
- hlist_del_rcu(&vxi->vx_hlist);
+ hlist_del(&vxi->vx_hlist);
put_vx_info(vxi);
}
/* __lookup_vx_info()
- * requires the rcu_read_lock()
+ * requires the hash_lock to be held
* doesn't increment the vx_refcnt */
static inline struct vx_info *__lookup_vx_info(xid_t xid)
{
struct hlist_head *head = &vx_info_hash[__hashval(xid)];
struct hlist_node *pos;
+ struct vx_info *vxi;
- hlist_for_each_rcu(pos, head) {
- struct vx_info *vxi =
- hlist_entry(pos, struct vx_info, vx_hlist);
+ vxd_assert_lock(&vx_info_hash_lock);
+ hlist_for_each(pos, head) {
+ vxi = hlist_entry(pos, struct vx_info, vx_hlist);
- if ((vxi->vx_id == xid) &&
- vx_info_state(vxi, VXS_HASHED))
- return vxi;
+ if (vxi->vx_id == xid)
+ goto found;
}
- return NULL;
+ vxi = NULL;
+found:
+ vxdprintk(VXD_CBIT(xid, 0),
+ "__lookup_vx_info(#%u): %p[#%u]",
+ xid, vxi, vxi?vxi->vx_id:0);
+ vxh_lookup_vx_info(xid, vxi);
+ return vxi;
}
static xid_t seq = MAX_S_CONTEXT;
xid_t barrier = seq;
+ vxd_assert_lock(&vx_info_hash_lock);
do {
if (++seq > MAX_S_CONTEXT)
seq = MIN_D_CONTEXT;
return 0;
}
+#ifdef CONFIG_VSERVER_LEGACY
+
/* __loc_vx_info()
* locate or create the requested context
return NULL;
}
+ /* required to make dynamic xids unique */
spin_lock(&vx_info_hash_lock);
/* dynamic context requested */
out_unlock:
spin_unlock(&vx_info_hash_lock);
+ vxh_loc_vx_info(id, vxi);
if (new)
__dealloc_vx_info(new);
return vxi;
}
+#endif
+
+/* __create_vx_info()
+
+ * create the requested context
+ * get() it and hash it */
+
+static struct vx_info * __create_vx_info(int id)
+{
+ struct vx_info *new, *vxi = NULL;
+
+ vxdprintk(VXD_CBIT(xid, 1), "create_vx_info(%d)*", id);
+
+ if (!(new = __alloc_vx_info(id))) {
+ return ERR_PTR(-ENOMEM);
+ }
+
+ /* required to make dynamic xids unique */
+ spin_lock(&vx_info_hash_lock);
+
+ /* dynamic context requested */
+ if (id == VX_DYNAMIC_ID) {
+ id = __vx_dynamic_id();
+ if (!id) {
+ printk(KERN_ERR "no dynamic context available.\n");
+ vxi = ERR_PTR(-EAGAIN);
+ goto out_unlock;
+ }
+ new->vx_id = id;
+ }
+ /* existing context requested */
+ else if ((vxi = __lookup_vx_info(id))) {
+ vxdprintk(VXD_CBIT(xid, 0),
+ "create_vx_info(%d) = %p (already there)", id, vxi);
+ if (vx_info_flags(vxi, VXF_STATE_SETUP, 0))
+ vxi = ERR_PTR(-EBUSY);
+ else
+ vxi = ERR_PTR(-EEXIST);
+ goto out_unlock;
+ }
+ /* dynamic xid creation blocker */
+ else if (id >= MIN_D_CONTEXT) {
+ vxdprintk(VXD_CBIT(xid, 0),
+ "create_vx_info(%d) (dynamic rejected)", id);
+ vxi = ERR_PTR(-EINVAL);
+ goto out_unlock;
+ }
+
+ /* new context requested */
+ vxdprintk(VXD_CBIT(xid, 0),
+ "create_vx_info(%d) = %p (new)", id, new);
+ __hash_vx_info(get_vx_info(new));
+ vxi = new, new = NULL;
+
+out_unlock:
+ spin_unlock(&vx_info_hash_lock);
+ vxh_create_vx_info(id, IS_ERR(vxi)?NULL:vxi);
+ if (new)
+ __dealloc_vx_info(new);
+ return vxi;
+}
/* exported stuff */
void unhash_vx_info(struct vx_info *vxi)
{
+ __shutdown_vx_info(vxi);
spin_lock(&vx_info_hash_lock);
__unhash_vx_info(vxi);
spin_unlock(&vx_info_hash_lock);
}
+
/* locate_vx_info()
* search for a vx_info and get() it
struct vx_info *locate_vx_info(int id)
{
- struct vx_info *vxi;
+ struct vx_info *vxi = NULL;
if (id < 0) {
vxi = get_vx_info(current->vx_info);
- } else {
- rcu_read_lock();
+ } else if (id > 1) {
+ spin_lock(&vx_info_hash_lock);
vxi = get_vx_info(__lookup_vx_info(id));
- rcu_read_unlock();
+ spin_unlock(&vx_info_hash_lock);
}
return vxi;
}
-/* vx_info_is_hashed()
+/* xid_is_hashed()
* verify that xid is still hashed */
-int vx_info_is_hashed(xid_t xid)
+int xid_is_hashed(xid_t xid)
{
int hashed;
- rcu_read_lock();
+ spin_lock(&vx_info_hash_lock);
hashed = (__lookup_vx_info(xid) != NULL);
- rcu_read_unlock();
+ spin_unlock(&vx_info_hash_lock);
return hashed;
}
#ifdef CONFIG_VSERVER_LEGACY
-#if 0
-struct vx_info *alloc_vx_info(xid_t xid)
-{
- return __alloc_vx_info(xid);
-}
-#endif
-
struct vx_info *locate_or_create_vx_info(int id)
{
int err;
{
int hindex, nr_xids = 0;
- rcu_read_lock();
for (hindex = 0; hindex < VX_HASH_SIZE; hindex++) {
struct hlist_head *head = &vx_info_hash[hindex];
struct hlist_node *pos;
- hlist_for_each_rcu(pos, head) {
+ spin_lock(&vx_info_hash_lock);
+ hlist_for_each(pos, head) {
struct vx_info *vxi;
if (--index > 0)
vxi = hlist_entry(pos, struct vx_info, vx_hlist);
xids[nr_xids] = vxi->vx_id;
- if (++nr_xids >= size)
+ if (++nr_xids >= size) {
+ spin_unlock(&vx_info_hash_lock);
goto out;
+ }
}
+ /* keep the lock time short */
+ spin_unlock(&vx_info_hash_lock);
}
out:
- rcu_read_unlock();
return nr_xids;
}
#endif
#include <linux/file.h>
-static inline int vx_nofiles_task(struct task_struct *tsk)
-{
- struct files_struct *files = tsk->files;
- unsigned long *obptr;
- int count, total;
-
- spin_lock(&files->file_lock);
- obptr = files->open_fds->fds_bits;
- count = files->max_fds / (sizeof(unsigned long) * 8);
- for (total = 0; count > 0; count--) {
- if (*obptr)
- total += hweight_long(*obptr);
- obptr++;
- }
- spin_unlock(&files->file_lock);
- return total;
-}
-
-#if 0
-
-static inline int vx_openfd_task(struct task_struct *tsk)
+static int vx_openfd_task(struct task_struct *tsk)
{
struct files_struct *files = tsk->files;
const unsigned long *bptr;
return total;
}
-#endif
-
/*
* migrate task to new context
* gets vxi, puts old_vxi on change
vxi->vx_id, atomic_read(&vxi->vx_usecnt));
if (!(ret = vx_migrate_user(p, vxi))) {
- int nofiles;
+ int openfd;
task_lock(p);
- // openfd = vx_openfd_task(p);
- nofiles = vx_nofiles_task(p);
+ openfd = vx_openfd_task(p);
if (old_vxi) {
atomic_dec(&old_vxi->cvirt.nr_threads);
atomic_dec(&old_vxi->cvirt.nr_running);
atomic_dec(&old_vxi->limit.rcur[RLIMIT_NPROC]);
/* FIXME: what about the struct files here? */
- // atomic_sub(nofiles, &old_vxi->limit.rcur[RLIMIT_NOFILE]);
- // atomic_sub(openfd, &old_vxi->limit.rcur[RLIMIT_OPENFD]);
+ atomic_sub(openfd, &old_vxi->limit.rcur[VLIMIT_OPENFD]);
}
atomic_inc(&vxi->cvirt.nr_threads);
atomic_inc(&vxi->cvirt.nr_running);
atomic_inc(&vxi->limit.rcur[RLIMIT_NPROC]);
/* FIXME: what about the struct files here? */
- // atomic_add(nofiles, &vxi->limit.rcur[RLIMIT_NOFILE]);
- // atomic_add(openfd, &vxi->limit.rcur[RLIMIT_OPENFD]);
+ atomic_add(openfd, &vxi->limit.rcur[VLIMIT_OPENFD]);
+
+ if (old_vxi) {
+ release_vx_info(old_vxi, p);
+ clr_vx_info(&p->vx_info);
+ }
+ claim_vx_info(vxi, p);
+ set_vx_info(&p->vx_info, vxi);
+ p->xid = vxi->vx_id;
vxdprintk(VXD_CBIT(xid, 5),
"moved task %p into vxi:%p[#%d]",
p, vxi, vxi->vx_id);
- /* should be handled in set_vx_info !! */
- if (old_vxi)
- clr_vx_info(&p->vx_info);
- set_vx_info(&p->vx_info, vxi);
- p->xid = vxi->vx_id;
vx_mask_bcaps(p);
task_unlock(p);
-
- /* obsoleted by clr/set */
- // put_vx_info(old_vxi);
}
out:
put_vx_info(old_vxi);
read_unlock(&tasklist_lock);
}
else
- xid = current->xid;
+ xid = vx_current_xid();
return xid;
}
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- if ((xid >= MIN_D_CONTEXT) && (xid != VX_DYNAMIC_ID))
+ if ((xid > MAX_S_CONTEXT) && (xid != VX_DYNAMIC_ID))
return -EINVAL;
- if (xid < 1)
+ if (xid < 2)
return -EINVAL;
- new_vxi = __loc_vx_info(xid, &ret);
- if (!new_vxi)
- return ret;
- if (!(new_vxi->vx_flags & VXF_STATE_SETUP)) {
- ret = -EEXIST;
- goto out_put;
- }
+ new_vxi = __create_vx_info(xid);
+ if (IS_ERR(new_vxi))
+ return PTR_ERR(new_vxi);
ret = new_vxi->vx_id;
vx_migrate_task(current, new_vxi);
/* if this fails, we might end up with a hashed vx_info */
-out_put:
put_vx_info(new_vxi);
return ret;
}
#include <linux/module.h>
-// EXPORT_SYMBOL_GPL(rcu_free_vx_info);
EXPORT_SYMBOL_GPL(free_vx_info);
-EXPORT_SYMBOL_GPL(vx_info_hash_lock);
-EXPORT_SYMBOL_GPL(unhash_vx_info);
git://git.onelab.eu / linux-2.6.git / blobdiff