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Made changes to have shared tcb parts in fs0 in preparation for clone()

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fs_data and files structures can now be shared in the vfs task.
Currently no means to free shared structures in tcb destruction. Need to add that.
This commit is contained in:
Bahadir Balban
2008-11-09 10:07:24 +02:00
parent 5468c1833d
commit 63fb907cd0
13 changed files with 189 additions and 78 deletions
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148
tasks/fs0/src/task.c
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@@ -10,6 +10,7 @@
#include <l4lib/arch/syslib.h>
#include <l4lib/ipcdefs.h>
#include <lib/malloc.h>
#include <lib/idpool.h>
#include <task.h>
#include <vfs.h>
#include <sys/ipc.h>
@@ -30,6 +31,7 @@ void global_add_task(struct tcb *task)
list_add_tail(&task->list, &global_tasks.list);
global_tasks.total++;
}
void global_remove_task(struct tcb *task)
{
BUG_ON(list_empty(&task->list));
@@ -37,7 +39,6 @@ void global_remove_task(struct tcb *task)
BUG_ON(--global_tasks.total < 0);
}
struct tcb *find_task(int tid)
{
struct tcb *t;
@@ -48,31 +49,112 @@ struct tcb *find_task(int tid)
return 0;
}
/* Allocate a task struct and initialise it */
struct tcb *create_tcb(void)
/* Allocate a vfs task structure according to given flags */
struct tcb *tcb_alloc_init(unsigned int flags)
{
struct tcb *t;
struct tcb *task;
if (!(t = kmalloc(sizeof(*t))))
if (!(task = kzalloc(sizeof(struct tcb))))
return PTR_ERR(-ENOMEM);
t->fdpool = id_pool_new_init(TASK_FILES_MAX);
INIT_LIST_HEAD(&t->list);
/* Allocate new fs data struct if its not shared */
if (!(flags & TCB_SHARED_FS)) {
if (!(task->fs_data =
kzalloc(sizeof(*task->fs_data)))) {
kfree(task);
return PTR_ERR(-ENOMEM);
}
task->fs_data->tcb_refs = 1;
}
return t;
/* Allocate file structures if not shared */
if (!(flags & TCB_SHARED_FILES)) {
if (!(task->files =
kzalloc(sizeof(*task->files)))) {
kfree(task->fs_data);
kfree(task);
return PTR_ERR(-ENOMEM);
}
if (IS_ERR(task->files->fdpool =
id_pool_new_init(TASK_FILES_MAX))) {
void *err = task->files->fdpool;
kfree(task->files);
kfree(task->fs_data);
kfree(task);
return err;
}
task->files->tcb_refs = 1;
}
/* Ids will be set up later */
task->tid = TASK_ID_INVALID;
/* Initialise list structure */
INIT_LIST_HEAD(&task->list);
return task;
}
void destroy_tcb(struct tcb *t)
void copy_tcb(struct tcb *to, struct tcb *from, unsigned int share_flags)
{
kfree(t->fdpool);
if (share_flags & TCB_SHARED_FILES) {
to->files = from->files;
to->files->tcb_refs++;
} else {
/* Copy all file descriptors */
memcpy(to->files->fd, from->files->fd,
TASK_FILES_MAX * sizeof(to->files->fd[0]));
global_remove_task(t);
kfree(t);
/* Copy the idpool */
id_pool_copy(to->files->fdpool, from->files->fdpool, TASK_FILES_MAX);
}
if (share_flags & TCB_SHARED_FS) {
to->fs_data = from->fs_data;
to->fs_data->tcb_refs++;
} else
memcpy(to->fs_data, from->fs_data, sizeof(*to->fs_data));
}
/* Allocate a task struct and initialise it */
struct tcb *tcb_create(struct tcb *orig, l4id_t tid, unsigned long utcb,
unsigned int share_flags)
{
struct tcb *task;
/* Can't have some share flags with no original task */
BUG_ON(!orig && share_flags);
/* Create a task and use given space and thread ids. */
if (IS_ERR(task = tcb_alloc_init(share_flags)))
return task;
task->tid = tid;
task->utcb_address = utcb;
/*
* If there's an original task that means this will be a full
* or partial copy of it. We copy depending on share_flags.
*/
if (orig)
copy_tcb(task, orig, share_flags);
return task;
}
/* FIXME: Modify it to work with shared structures!!! */
void tcb_destroy(struct tcb *task)
{
global_remove_task(task);
kfree(task);
}
/*
* Attaches to task's utcb. FIXME: Add SHM_RDONLY and test it.
* Attaches to task's utcb. TODO: Add SHM_RDONLY and test it.
* FIXME: This calls the pager and is a potential for deadlock
* it only doesn't lock because it is called during initialisation.
*/
int task_utcb_attach(struct tcb *t)
{
@@ -106,32 +188,19 @@ out_err:
* Receives ipc from pager about a new fork event and
* the information on the resulting child task.
*/
int pager_notify_fork(struct tcb *sender, l4id_t parid,
l4id_t chid, unsigned long utcb_address)
int pager_notify_fork(struct tcb *sender, l4id_t parentid,
l4id_t childid, unsigned long utcb_address,
unsigned int flags)
{
struct tcb *child, *parent;
// printf("%s/%s\n", __TASKNAME__, __FUNCTION__);
BUG_ON(!(parent = find_task(parid)));
BUG_ON(!(parent = find_task(parentid)));
if (IS_ERR(child = create_tcb()))
/* Create a child vfs tcb using given parent and copy flags */
if (IS_ERR(child = tcb_create(parent, childid, utcb_address, flags)))
return (int)child;
/* Initialise fields sent by pager */
child->tid = chid;
child->utcb_address = utcb_address;
/*
* Initialise vfs specific fields.
* FIXME: Or copy from parent???
*/
child->rootdir = vfs_root.pivot;
child->curdir = vfs_root.pivot;
/* Copy file descriptors from parent */
id_pool_copy(child->fdpool, parent->fdpool, TASK_FILES_MAX);
memcpy(child->fd, parent->fd, TASK_FILES_MAX * sizeof(int));
global_add_task(child);
// printf("%s/%s: Exiting...\n", __TASKNAME__, __FUNCTION__);
@@ -149,7 +218,7 @@ int pager_notify_exit(struct tcb *sender, l4id_t tid)
// printf("%s/%s\n", __TASKNAME__, __FUNCTION__);
BUG_ON(!(task = find_task(tid)));
destroy_tcb(task);
tcb_destroy(task);
// printf("%s/%s: Exiting...\n", __TASKNAME__, __FUNCTION__);
@@ -188,16 +257,15 @@ int init_task_structs(struct task_data_head *tdata_head)
struct tcb *t;
for (int i = 0; i < tdata_head->total; i++) {
if (IS_ERR(t = create_tcb()))
/* New tcb with fields sent by pager */
if (IS_ERR(t = tcb_create(0, tdata_head->tdata[i].tid,
tdata_head->tdata[i].utcb_address,
0)))
return (int)t;
/* Initialise fields sent by pager */
t->tid = tdata_head->tdata[i].tid;
t->utcb_address = tdata_head->tdata[i].utcb_address;
/* Initialise vfs specific fields. */
t->rootdir = vfs_root.pivot;
t->curdir = vfs_root.pivot;
t->fs_data->rootdir = vfs_root.pivot;
t->fs_data->curdir = vfs_root.pivot;
/* Print task information */
//printf("%s: Task info received from mm0:\n", __TASKNAME__);