It is overseen by Twilight Sparkle ;)
- 1. Get inodes hooked into lru
- 2. Get dnodes hooked into lru
+ 1. Get inodes hooked into lru (CHECKED)
+ 2. Get dnodes hooked into lru (CHECKED)
3. Get inodes properly hashed so they can be reused by underling fs (CHECKED)
- 4. (lru) Add a callback function (or destructor) for eviction.
+ 4. (lru) Add a callback function (or destructor) for eviction. (CHECKED)
[good idea] or a constructor/destructor pattern in cake allocator ?
5. (mount) Figure out a way to identify a busy mount point before unmount
maybe a unified mount_point structure that maintain a referencing
#define HASH_MASK (HASHTABLE_SIZE - 1)
#define HASHBITS (32 - HASHTABLE_BITS)
-#define lock_inode(inode) mutex_lock(&inode->lock)
#define unlock_inode(inode) mutex_unlock(&inode->lock)
+#define lock_inode(inode) \
+ ({ \
+ mutex_lock(&inode->lock); \
+ lru_use_one(inode_lru, &inode->lru); \
+ })
-#define lock_dnode(dnode) mutex_lock(&dnode->lock)
#define unlock_dnode(dnode) mutex_unlock(&dnode->lock)
+#define lock_dnode(dnode) \
+ ({ \
+ mutex_lock(&dnode->lock); \
+ lru_use_one(dnode_lru, &dnode->lru); \
+ })
static struct cake_pile* dnode_pile;
static struct cake_pile* inode_pile;
static struct v_superblock* root_sb;
static struct hbucket *dnode_cache, *inode_cache;
+static struct lru_zone *dnode_lru, *inode_lru;
+
struct hstr vfs_ddot = HSTR("..", 2);
struct hstr vfs_dot = HSTR(".", 1);
struct hstr vfs_empty = HSTR("", 0);
void
vfs_sb_free(struct v_superblock* sb);
+static int
+__vfs_try_evict_dnode(struct lru_node* obj);
+
+static int
+__vfs_try_evict_inode(struct lru_node* obj);
+
void
vfs_init()
{
dnode_cache = vzalloc(HASHTABLE_SIZE * sizeof(struct hbucket));
inode_cache = vzalloc(HASHTABLE_SIZE * sizeof(struct hbucket));
+ dnode_lru = lru_new_zone(__vfs_try_evict_dnode);
+ inode_lru = lru_new_zone(__vfs_try_evict_inode);
+
hstr_rehash(&vfs_ddot, HSTR_FULL_HASH);
hstr_rehash(&vfs_dot, HSTR_FULL_HASH);
// 创建一个根superblock，用来蕴含我们的根目录。
root_sb = vfs_sb_alloc();
root_sb->root = vfs_d_alloc();
- root_sb->root->inode = vfs_i_alloc(root_sb, 0);
}
inline struct hbucket*
if (!dnode) {
dnode = vfs_d_alloc();
+ if (!dnode) {
+ errno = ENOMEM;
+ goto error;
+ }
+
hstrcpy(&dnode->name, &name);
lock_inode(current_level->inode);
if (errno) {
unlock_dnode(current_level);
vfree(dnode->name.value);
- goto error;
+ goto cleanup;
}
vfs_dcache_add(current_level, dnode);
*dentry = current_level;
return 0;
-error:
+cleanup:
vfs_d_free(dnode);
+error:
*dentry = NULL;
return errno;
}
int errno = __vfs_walk(start, path, &interim, component, options);
int counter = 0;
- while (!errno) {
+ while (!errno && interim->inode && (options & VFS_WALK_NOFOLLOW)) {
if (counter >= VFS_MAX_SYMLINK) {
errno = ELOOP;
continue;
}
if ((interim->inode->itype & VFS_IFSYMLINK) &&
- !(options & VFS_WALK_NOFOLLOW) &&
interim->inode->ops.read_symlink) {
+
+ lock_inode(interim->inode);
errno = interim->inode->ops.read_symlink(interim->inode, &pathname);
+ unlock_inode(interim->inode);
+
if (errno) {
break;
}
struct device* device,
struct v_dnode* mnt_point)
{
- if (!(mnt_point->inode->itype & VFS_IFDIR)) {
+ if (mnt_point->inode && !(mnt_point->inode->itype & VFS_IFDIR)) {
return ENOTDIR;
}
return errno;
}
+void
+vfs_assign_inode(struct v_dnode* assign_to, struct v_inode* inode)
+{
+ if (assign_to->inode) {
+ assign_to->inode->link_count--;
+ }
+ assign_to->inode = inode;
+ inode->link_count++;
+}
+
int
vfs_link(struct v_dnode* to_link, struct v_dnode* name)
{
} else if (!to_link->inode->ops.link) {
errno = ENOTSUP;
} else if (!(errno = to_link->inode->ops.link(to_link->inode, name))) {
- name->inode = to_link->inode;
- to_link->inode->link_count++;
+ vfs_assign_inode(name, to_link->inode);
}
unlock_inode(to_link->inode);
cake_release(superblock_pile, sb);
}
+static int
+__vfs_try_evict_dnode(struct lru_node* obj)
+{
+ struct v_dnode* dnode = container_of(obj, struct v_dnode, lru);
+
+ if (!dnode->ref_count) {
+ vfs_d_free(dnode);
+ return 1;
+ }
+ return 0;
+}
+
+static int
+__vfs_try_evict_inode(struct lru_node* obj)
+{
+ struct v_inode* inode = container_of(obj, struct v_inode, lru);
+
+ if (!inode->link_count && !inode->open_count) {
+ vfs_i_free(inode);
+ return 1;
+ }
+ return 0;
+}
+
struct v_dnode*
vfs_d_alloc()
{
struct v_dnode* dnode = cake_grab(dnode_pile);
+ if (!dnode) {
+ lru_evict_half(dnode_lru);
+
+ if (!(dnode = cake_grab(dnode_pile))) {
+ return NULL;
+ }
+ }
+
memset(dnode, 0, sizeof(*dnode));
llist_init_head(&dnode->children);
llist_init_head(&dnode->siblings);
dnode->ref_count = ATOMIC_VAR_INIT(0);
dnode->name = HHSTR(vzalloc(VFS_NAME_MAXLEN), 0, 0);
+ lru_use_one(dnode_lru, &dnode->lru);
+
return dnode;
}
void
vfs_d_free(struct v_dnode* dnode)
{
- if (dnode->ref_count) {
- // it can be only freed if no one is refering
- return;
- }
- if (dnode->inode && dnode->inode->link_count) {
+ assert(dnode->ref_count == 0);
+
+ if (dnode->inode) {
+ assert(dnode->inode->link_count > 0);
dnode->inode->link_count--;
}
// 这也就是说，每个 v_inode 的 id
// 必须要由设备ID，和该虚拟inode缓存所对应的物理inode
// 相对于其所在的文件系统的id，进行组成！
- inode_id = hash_32(inode_id ^ device_id, HASH_SIZE_BITS);
+ inode_id = hash_32(inode_id ^ (-device_id), HASH_SIZE_BITS);
inode_id = (inode_id >> HASHBITS) ^ inode_id;
struct hbucket* slot = &inode_cache[inode_id & HASH_MASK];
hashtable_bucket_foreach(slot, pos, n, hash_list)
{
if (pos->id == inode_id) {
- return pos;
+ goto done;
+ }
+ }
+
+ if (!(pos = cake_grab(inode_pile))) {
+ lru_evict_half(inode_lru);
+ if (!(pos = cake_grab(inode_pile))) {
+ return NULL;
}
}
- pos = cake_grab(inode_pile);
memset(pos, 0, sizeof(*pos));
pos->id = inode_id;
- pos->link_count = 1;
mutex_init(&pos->lock);
hlist_add(&slot->head, &pos->hash_list);
+done:
+ lru_use_one(inode_lru, &pos->lru);
return pos;
}
struct v_dnode* parent = *fdir;
struct v_dnode* file_new = vfs_d_alloc();
+
+ if (!file_new) {
+ return ENOMEM;
+ }
+
hstrcpy(&file_new->name, &name);
+ lock_dnode(parent);
+
if (!(errno = parent->inode->ops.create(parent->inode, file_new))) {
*file = file_new;
vfs_d_free(file_new);
}
+ unlock_dnode(parent);
+
return errno;
}
__SYSCALL_INTERRUPTIBLE(
{ errno = file->ops.read(file->inode, buf, count, file->f_pos); })
- unlock_inode(file->inode);
-
if (errno > 0) {
file->f_pos += errno;
+ unlock_inode(file->inode);
return errno;
}
+ unlock_inode(file->inode);
+
done:
return DO_STATUS(errno);
}
__SYSCALL_INTERRUPTIBLE(
{ errno = file->ops.write(file->inode, buf, count, file->f_pos); })
- unlock_inode(file->inode);
-
if (errno > 0) {
file->f_pos += errno;
+ unlock_inode(file->inode);
return errno;
}
+ unlock_inode(file->inode);
+
done:
return DO_STATUS(errno);
}
lock_dnode(dnode);
- if (dnode->parent)
- lock_dnode(dnode->parent);
-
if ((dnode->super_block->fs->types & FSTYPE_ROFS)) {
errno = EROFS;
goto done;
}
- if (dnode->ref_count || dnode->inode->open_count) {
+ if (dnode->ref_count > 1 || dnode->inode->open_count) {
errno = EBUSY;
goto done;
}
goto done;
}
- lock_inode(dnode->inode);
+ struct v_dnode* parent = dnode->parent;
+
+ if (!parent) {
+ errno = EINVAL;
+ goto done;
+ }
+
+ lock_dnode(parent);
+ lock_inode(parent->inode);
if ((dnode->inode->itype & VFS_IFDIR)) {
- errno = dnode->inode->ops.rmdir(dnode->inode);
+ errno = parent->inode->ops.rmdir(parent->inode, dnode);
if (!errno) {
vfs_dcache_remove(dnode);
- unlock_inode(dnode->inode);
- vfs_d_free(dnode);
-
- goto done;
}
} else {
errno = ENOTDIR;
}
- unlock_inode(dnode->inode);
+ unlock_inode(parent->inode);
+ unlock_dnode(parent);
done:
unlock_dnode(dnode);
- if (dnode->parent)
- unlock_dnode(dnode->parent);
return DO_STATUS(errno);
}
__DEFINE_LXSYSCALL1(int, mkdir, const char*, path)
{
+ int errno = 0;
struct v_dnode *parent, *dir = vfs_d_alloc();
- int errno =
- vfs_walk(__current->cwd, path, &parent, &dir->name, VFS_WALK_PARENT);
- if (errno) {
+
+ if (!dir) {
+ errno = ENOMEM;
+ goto done;
+ }
+
+ if ((errno = vfs_walk(
+ __current->cwd, path, &parent, &dir->name, VFS_WALK_PARENT))) {
goto done;
}
// symlink case
errno = inode->ops.unlink(inode);
if (!errno) {
- inode->link_count--;
vfs_dcache_remove(dnode);
vfs_d_free(dnode);
}
errno = EROFS;
goto done;
}
- if (!dnode->inode->ops.symlink) {
+ if (!dnode->inode->ops.set_symlink) {
errno = ENOTSUP;
goto done;
}
lock_inode(dnode->inode);
- errno = dnode->inode->ops.symlink(dnode->inode, link_target);
+ errno = dnode->inode->ops.set_symlink(dnode->inode, link_target);
unlock_inode(dnode->inode);
errno = vfs_walk(target_parent, name.value, &target, NULL, 0);
if (errno == ENOENT) {
target = vfs_d_alloc();
- hstrcpy(&target->name, &name);
} else if (errno) {
goto done;
}
+ if (!target) {
+ errno = ENOMEM;
+ goto done;
+ }
+
+ hstrcpy(&target->name, &name);
+
if (!(errno = vfs_do_rename(cur, target))) {
vfs_d_free(target);
}
git://scm.lunaixsky.com / lunaix-os.git / commitdiff