mirror of
https://github.com/drasko/codezero.git
synced 2026-01-18 22:03:16 +01:00
73058dc249
close() needs to flush dirty buffers. pager needs to have read/write support properly implemented. open() needs to record mode and access times. The need for access times means we need rtc and time implementation. Also need to add stat() access() etc.
85 lines
1.9 KiB
C
85 lines
1.9 KiB
C
/*
|
|
* High-level vfs implementation.
|
|
*
|
|
* Copyright (C) 2008 Bahadir Balban
|
|
*/
|
|
#include <fs.h>
|
|
#include <vfs.h>
|
|
#include <task.h>
|
|
#include <path.h>
|
|
|
|
LIST_HEAD(vnode_cache);
|
|
LIST_HEAD(dentry_cache);
|
|
|
|
/*
|
|
* /
|
|
* /boot
|
|
* /boot/images/mm0.axf
|
|
* /boot/images/fs0.axf
|
|
* /boot/images/test0.axf
|
|
* /file.txt
|
|
*/
|
|
struct vfs_mountpoint vfs_root;
|
|
|
|
/*
|
|
* Vnodes in the vnode cache have 2 keys. One is their dentry names, the other
|
|
* is their vnum. This one checks the vnode cache by the given vnum first.
|
|
* If nothing is found, it reads the vnode from disk into cache. This is called
|
|
* by system calls since tasks keep an fd-to-vnum table.
|
|
*/
|
|
struct vnode *vfs_lookup_byvnum(struct superblock *sb, unsigned long vnum)
|
|
{
|
|
struct vnode *v;
|
|
int err;
|
|
|
|
/* Check the vnode flat list by vnum */
|
|
list_for_each_entry(v, &vnode_cache, cache_list)
|
|
if (v->vnum == vnum)
|
|
return v;
|
|
|
|
/* Check the actual filesystem for the vnode */
|
|
v = vfs_alloc_vnode();
|
|
v->vnum = vnum;
|
|
|
|
/* Note this only checks given superblock */
|
|
if ((err = sb->ops->read_vnode(sb, v)) < 0) {
|
|
vfs_free_vnode(v);
|
|
return PTR_ERR(err);
|
|
}
|
|
|
|
/* Add the vnode back to vnode flat list */
|
|
list_add(&v->cache_list, &vnode_cache);
|
|
|
|
return v;
|
|
}
|
|
|
|
/*
|
|
* Vnodes in the vnode cache have 2 keys. One is the set of dentry names they
|
|
* have, the other is their vnum. This one checks the vnode cache by the path
|
|
* first. If nothing is found, it reads the vnode from disk into the cache.
|
|
*/
|
|
struct vnode *vfs_lookup_bypath(struct pathdata *pdata)
|
|
{
|
|
const char *firstcomp;
|
|
|
|
/*
|
|
* This does vfs cache + fs lookup.
|
|
*/
|
|
BUG_ON(list_empty(&pdata->list));
|
|
firstcomp = pathdata_next_component(pdata);
|
|
return pdata->vstart->ops.lookup(pdata->vstart, pdata, firstcomp);
|
|
}
|
|
|
|
int vfs_mount_root(struct superblock *sb)
|
|
{
|
|
/*
|
|
* Lookup the root vnode of this superblock.
|
|
* The root superblock has vnode number 0.
|
|
*/
|
|
vfs_root.pivot = vfs_lookup_byvnum(sb, 0);
|
|
vfs_root.sb = sb;
|
|
|
|
return 0;
|
|
}
|
|
|