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#include "errno.h"
#include "globals.h"
#include "kernel.h"
#include "util/string.h"
#include <fs/s5fs/s5fs.h>
#include <fs/vnode.h>
#include "fs/file.h"
#include "fs/ramfs/ramfs.h"
#include "mm/kmalloc.h"
#include "mm/slab.h"
#include "util/debug.h"
#ifdef __S5FS__
#include "fs/s5fs/s5fs.h"
#endif
#ifdef __MOUNTING__
/* The fs listed here are only the non-root file systems */
list_t mounted_fs_list;
/*
* Implementing this function is not required and strongly discouraged unless
* you are absolutley sure your Weenix is perfect.
*
* The purpose of this function is to set up the pointers between the file
* system struct and the vnode of the mount point. Remember to watch your
* reference counts. (The exception here is when the vnode's vn_mount field
* points to the mounted file system's root we do not increment the reference
* count on the file system's root vnode. The file system is already keeping
* a reference to the vnode which will not go away until the file system is
* unmounted. If we kept a second such reference it would conflict with the
* behavior of vfs_is_in_use(), make sure you understand why.)
*
* Once everything is set up add the file system to the list of mounted file
* systems.
*
* Remember proper error handling.
*
* This function is not meant to mount the root file system.
*/
int vfs_mount(struct vnode *mtpt, fs_t *fs)
{
NOT_YET_IMPLEMENTED("MOUNTING: ***none***");
return -EINVAL;
}
/*
* Implementing this function is not required and strongly discouraged unless
* you are absolutley sure your Weenix is perfect.
*
* The purpose of this function is to undo the setup done in vfs_mount(). Also
* you should call the underlying file system's umount() function. Make sure
* to keep track of reference counts. You should also kfree the fs struct at
* the end of this method.
*
* Remember proper error handling. You might want to make sure that you do not
* try to call this function on the root file system (this function is not meant
* to unmount the root file system).
*/
int vfs_umount(fs_t *fs)
{
NOT_YET_IMPLEMENTED("MOUNTING: ***none***");
return -EINVAL;
}
#endif /* __MOUNTING__ */
fs_t vfs_root_fs = {
.fs_dev = VFS_ROOTFS_DEV,
.fs_type = VFS_ROOTFS_TYPE,
.vnode_list = LIST_INITIALIZER(vfs_root_fs.vnode_list),
.vnode_list_mutex = KMUTEX_INITIALIZER(vfs_root_fs.vnode_list_mutex),
.fs_vnode_allocator = NULL,
.fs_i = NULL,
.fs_ops = NULL,
.fs_root = NULL,
};
/*
* Call mountfunc on vfs_root_fs and set curproc->p_cwd (reference count!)
*/
void vfs_init()
{
long err = mountfunc(&vfs_root_fs);
if (err)
{
panic(
"Failed to mount root fs of type \"%s\" on device "
"\"%s\" with errno of %ld\n",
vfs_root_fs.fs_type, vfs_root_fs.fs_dev, -err);
}
vlock(vfs_root_fs.fs_root);
vref(curproc->p_cwd = vfs_root_fs.fs_root);
vunlock(vfs_root_fs.fs_root);
#ifdef __MOUNTING__
list_init(&mounted_fs_list);
fs->fs_mtpt = vfs_root_fs.fs_root;
#endif
}
/*
* Wrapper around the sync call() to vfs_root_fs using fs_ops
*/
void do_sync()
{
vfs_root_fs.fs_ops->sync(&vfs_root_fs);
#ifdef __MOUNTING__
// if implementing mounting, just sync() all the mounted FS's as well
#endif
}
/*
*
*/
long vfs_shutdown()
{
dbg(DBG_VFS, "shutting down vfs\n");
long ret = 0;
#ifdef __MOUNTING__
list_iterate(&mounted_fs_list, mtfs, fs_t, fs_link)
{
ret = vfs_umount(mtfs);
KASSERT(!ret);
}
#endif
if (vfs_is_in_use(&vfs_root_fs))
{
panic("vfs_shutdown: found active vnodes in root filesystem");
}
if (vfs_root_fs.fs_ops->umount)
{
ret = vfs_root_fs.fs_ops->umount(&vfs_root_fs);
}
else
{
// vlock(vfs_root_fs.fs_root);
vput(&vfs_root_fs.fs_root);
}
if (vfs_count_active_vnodes(&vfs_root_fs))
{
panic(
"vfs_shutdown: vnodes still in use after unmounting root "
"filesystem");
}
return ret;
}
long mountfunc(fs_t *fs)
{
static const struct
{
char *fstype;
long (*mountfunc)(fs_t *);
} types[] = {
#ifdef __S5FS__
{"s5fs", s5fs_mount},
#endif
{"ramfs", ramfs_mount},
};
for (unsigned int i = 0; i < sizeof(types) / sizeof(types[0]); i++)
{
if (strcmp(fs->fs_type, types[i].fstype) == 0)
{
return types[i].mountfunc(fs);
}
}
return -EINVAL;
}
/*
* A filesystem is in use if the total number of vnode refcounts for that
* filesystem > 1. The singular refcount in a fs NOT in use comes from fs_root.
*
* Error cases vfs_is_in_use is responsible for generating:
* - EBUSY: if the filesystem is in use
*/
long vfs_is_in_use(fs_t *fs)
{
long ret = 0;
// kmutex_lock(&fs->vnode_list_mutex);
list_iterate(&fs->vnode_list, vn, vnode_t, vn_link)
{
vlock(vn);
size_t expected_refcount = vn->vn_fs->fs_root == vn ? 1 : 0;
size_t refcount = vn->vn_mobj.mo_refcount;
vunlock(vn);
if (refcount != expected_refcount)
{
dbg(DBG_VFS,
"vnode %d still in use with %d references and %lu mobj "
"references (expected %lu)\n",
vn->vn_vno, vn->vn_mobj.mo_refcount, refcount,
expected_refcount);
ret = -EBUSY;
// break;
}
}
// kmutex_unlock(&fs->vnode_list_mutex);
return ret;
}
/*
* Return the size of fs->vnode_list
*/
size_t vfs_count_active_vnodes(fs_t *fs)
{
size_t count = 0;
kmutex_lock(&fs->vnode_list_mutex);
list_iterate(&fs->vnode_list, vn, vnode_t, vn_link) { count++; }
kmutex_unlock(&fs->vnode_list_mutex);
return count;
}
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