maybe a unified mount_point structure that maintain a referencing
counter on any dnodes within the subtree? Such a counter will only
increament if a file is opened or a dnode is being used as working
- directory and decreamenting conversely.
+ directory and decreamenting conversely. (CHECKED)
6. (mount) Ability to track all mount points (including sub-mounts)
- so we can be confident to clean up everything when we unmount.
+ so we can be confident to clean up everything when we
+ unmount. (CHECKED)
7. (mount) Figure out a way to acquire the device represented by a dnode.
so it can be used to mount. (e.g. we wish to get `struct device*`
out of the dnode at /dev/sda)
[tip] we should pay attention at twifs and add a private_data field
- under struct v_dnode?
- 8. (mount) Then, we should refactor on mount/unmount mechanism.
+ under struct v_dnode? (CHECKED)
+ 8. (mount) Then, we should refactor on mount/unmount mechanism. (CHECKED)
9. (mount) (future) Ability to mount any thing? e.g. Linux can mount a disk
image file using a so called "loopback" pseudo device. Maybe
we can do similar thing in Lunaix? A block device emulation
#include <lunaix/fs/twifs.h>
-#define PATH_DELIM '/'
-#define HASHTABLE_BITS 10
-#define HASHTABLE_SIZE (1 << HASHTABLE_BITS)
-#define HASH_MASK (HASHTABLE_SIZE - 1)
-#define HASHBITS (32 - HASHTABLE_BITS)
-
-#define unlock_inode(inode) mutex_unlock(&inode->lock)
-#define lock_inode(inode) \
- ({ \
- mutex_lock(&inode->lock); \
- lru_use_one(inode_lru, &inode->lru); \
- })
-
-#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 cake_pile* file_pile;
static struct cake_pile* superblock_pile;
static struct cake_pile* fd_pile;
-static struct v_superblock* root_sb;
-static struct hbucket *dnode_cache, *inode_cache;
+struct v_dnode* vfs_sysroot;
+static struct hbucket* dnode_cache;
-static struct lru_zone *dnode_lru, *inode_lru;
+struct lru_zone *dnode_lru, *inode_lru;
struct hstr vfs_ddot = HSTR("..", 2);
struct hstr vfs_dot = HSTR(".", 1);
superblock_pile =
cake_new_pile("sb_cache", sizeof(struct v_superblock), 1, 0);
- dnode_cache = vzalloc(HASHTABLE_SIZE * sizeof(struct hbucket));
- inode_cache = vzalloc(HASHTABLE_SIZE * sizeof(struct hbucket));
+ dnode_cache = vzalloc(VFS_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();
+ // 创建一个根dnode。
+ vfs_sysroot = vfs_d_alloc(NULL, &vfs_empty);
+ vfs_sysroot->parent = vfs_sysroot;
+ atomic_fetch_add(&vfs_sysroot->ref_count, 1);
}
inline struct hbucket*
// 与parent的指针值做加法，来减小碰撞的可能性。
_hash += (uint32_t)parent;
// 确保低位更加随机
- _hash = _hash ^ (_hash >> HASHBITS);
+ _hash = _hash ^ (_hash >> VFS_HASHBITS);
*hash = _hash;
- return &dnode_cache[_hash & HASH_MASK];
+ return &dnode_cache[_hash & VFS_HASH_MASK];
}
struct v_dnode*
return parent;
if (HSTR_EQ(str, &vfs_ddot)) {
- return parent->parent ? parent->parent : parent;
+ return parent->parent;
}
uint32_t hash = str->hash;
void
vfs_dcache_add(struct v_dnode* parent, struct v_dnode* dnode)
{
+ assert(parent);
+
atomic_fetch_add(&dnode->ref_count, 1);
dnode->parent = parent;
llist_append(&parent->children, &dnode->siblings);
+
struct hbucket* bucket = __dcache_hash(parent, &dnode->name.hash);
hlist_add(&bucket->head, &dnode->hash_list);
}
void
vfs_dcache_remove(struct v_dnode* dnode)
{
+ assert(dnode);
assert(dnode->ref_count == 1);
llist_delete(&dnode->siblings);
void
vfs_dcache_rehash(struct v_dnode* new_parent, struct v_dnode* dnode)
{
+ assert(new_parent);
+
hstr_rehash(&dnode->name, HSTR_FULL_HASH);
vfs_dcache_remove(dnode);
vfs_dcache_add(new_parent, dnode);
}
-int
-__vfs_walk(struct v_dnode* start,
- const char* path,
- struct v_dnode** dentry,
- struct hstr* component,
- int walk_options)
-{
- int errno = 0;
- int i = 0, j = 0;
-
- if (path[0] == PATH_DELIM || !start) {
- if ((walk_options & VFS_WALK_FSRELATIVE) && start) {
- start = start->super_block->root;
- } else {
- start = root_sb->root;
- }
- i++;
- }
-
- struct v_dnode* dnode;
- struct v_dnode* current_level = start;
-
- char name_content[VFS_NAME_MAXLEN];
- struct hstr name = HSTR(name_content, 0);
-
- char current = path[i++], lookahead;
- while (current) {
- lookahead = path[i++];
- if (current != PATH_DELIM) {
- if (j >= VFS_NAME_MAXLEN - 1) {
- return ENAMETOOLONG;
- }
- if (!VFS_VALID_CHAR(current)) {
- return EINVAL;
- }
- name_content[j++] = current;
- if (lookahead) {
- goto cont;
- }
- }
-
- // handling cases like /^.*(\/+).*$/
- if (lookahead == PATH_DELIM) {
- goto cont;
- }
-
- lock_dnode(current_level);
-
- name_content[j] = 0;
- name.len = j;
- hstr_rehash(&name, HSTR_FULL_HASH);
-
- if (!lookahead && (walk_options & VFS_WALK_PARENT)) {
- if (component) {
- component->hash = name.hash;
- component->len = j;
- strcpy(component->value, name_content);
- }
- unlock_dnode(current_level);
- break;
- }
-
- dnode = vfs_dcache_lookup(current_level, &name);
-
- if (!dnode) {
- dnode = vfs_d_alloc();
-
- if (!dnode) {
- errno = ENOMEM;
- goto error;
- }
-
- hstrcpy(&dnode->name, &name);
-
- lock_inode(current_level->inode);
-
- errno =
- current_level->inode->ops.dir_lookup(current_level->inode, dnode);
-
- if (errno == ENOENT && (walk_options & VFS_WALK_MKPARENT)) {
- if (!current_level->inode->ops.mkdir) {
- errno = ENOTSUP;
- } else {
- errno = current_level->inode->ops.mkdir(
- current_level->inode, dnode);
- }
- }
-
- unlock_inode(current_level->inode);
-
- if (errno) {
- unlock_dnode(current_level);
- vfree(dnode->name.value);
- goto cleanup;
- }
-
- vfs_dcache_add(current_level, dnode);
- }
-
- unlock_dnode(current_level);
-
- j = 0;
- current_level = dnode;
- cont:
- current = lookahead;
- };
-
- *dentry = current_level;
- return 0;
-
-cleanup:
- vfs_d_free(dnode);
-error:
- *dentry = NULL;
- return errno;
-}
-
-#define VFS_MAX_SYMLINK 16
-
-int
-vfs_walk(struct v_dnode* start,
- const char* path,
- struct v_dnode** dentry,
- struct hstr* component,
- int options)
-{
- struct v_dnode* interim;
- const char* pathname = path;
- int errno = __vfs_walk(start, path, &interim, component, options);
- int counter = 0;
-
- while (!errno && interim->inode && (options & VFS_WALK_NOFOLLOW)) {
- if (counter >= VFS_MAX_SYMLINK) {
- errno = ELOOP;
- continue;
- }
- if ((interim->inode->itype & VFS_IFSYMLINK) &&
- 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;
- }
- } else {
- break;
- }
- errno = __vfs_walk(start, pathname, &interim, component, options);
- counter++;
- }
-
- *dentry = errno ? 0 : interim;
-
- return errno;
-}
-
-int
-vfs_mount(const char* target, const char* fs_name, struct device* device)
-{
- int errno;
- struct v_dnode* mnt;
-
- if (!(errno = vfs_walk(__current->cwd, target, &mnt, NULL, 0))) {
- errno = vfs_mount_at(fs_name, device, mnt);
- }
-
- return errno;
-}
-
-int
-vfs_unmount(const char* target)
-{
- int errno;
- struct v_dnode* mnt;
-
- if (!(errno = vfs_walk(__current->cwd, target, &mnt, NULL, 0))) {
- errno = vfs_unmount_at(mnt);
- }
-
- return errno;
-}
-
-int
-vfs_mount_at(const char* fs_name,
- struct device* device,
- struct v_dnode* mnt_point)
-{
- if (mnt_point->inode && !(mnt_point->inode->itype & VFS_IFDIR)) {
- return ENOTDIR;
- }
-
- struct filesystem* fs = fsm_get(fs_name);
- if (!fs) {
- return ENODEV;
- }
-
- struct v_superblock* sb = vfs_sb_alloc();
- sb->dev = device;
- sb->fs_id = fs->fs_id;
-
- int errno = 0;
- if (!(errno = fs->mount(sb, mnt_point))) {
- sb->fs = fs;
- sb->root = mnt_point;
- mnt_point->super_block = sb;
- llist_append(&root_sb->sb_list, &sb->sb_list);
- }
-
- return errno;
-}
-
-int
-vfs_unmount_at(struct v_dnode* mnt_point)
-{
- // FIXME deal with the detached dcache subtree
- int errno = 0;
- struct v_superblock* sb = mnt_point->super_block;
- if (!sb) {
- return EINVAL;
- }
-
- if (sb->root != mnt_point) {
- return EINVAL;
- }
-
- if (!(errno = sb->fs->unmount(sb))) {
- struct v_dnode* fs_root = sb->root;
- vfs_dcache_remove(fs_root);
-
- llist_delete(&sb->sb_list);
- vfs_sb_free(sb);
- vfs_d_free(fs_root);
- }
- return errno;
-}
-
int
vfs_open(struct v_dnode* dnode, struct v_file** file)
{
- if (!dnode->inode || !dnode->inode->ops.open) {
+ if (!dnode->inode || !dnode->inode->ops->open) {
return ENOTSUP;
}
struct v_inode* inode = dnode->inode;
+
+ lock_inode(inode);
+
struct v_file* vfile = cake_grab(file_pile);
memset(vfile, 0, sizeof(*vfile));
inode->pg_cache = pcache;
}
- int errno = inode->ops.open(inode, vfile);
+ int errno = inode->ops->open(inode, vfile);
if (errno) {
cake_release(file_pile, vfile);
} else {
atomic_fetch_add(&dnode->ref_count, 1);
inode->open_count++;
+ mnt_mkbusy(dnode->mnt);
*file = vfile;
}
+ unlock_inode(inode);
+
return errno;
}
{
int errno;
+ if ((errno = vfs_check_writable(to_link))) {
+ return errno;
+ }
+
lock_inode(to_link->inode);
if (to_link->super_block->root != name->super_block->root) {
errno = EXDEV;
- } else if (!to_link->inode->ops.link) {
+ } else if (!to_link->inode->ops->link) {
errno = ENOTSUP;
- } else if (!(errno = to_link->inode->ops.link(to_link->inode, name))) {
+ } else if (!(errno = to_link->inode->ops->link(to_link->inode, name))) {
vfs_assign_inode(name, to_link->inode);
}
unlock_inode(to_link->inode);
}
int
-vfs_close(struct v_file* file)
+vfs_pclose(struct v_file* file, pid_t pid)
{
int errno = 0;
- if (!file->ops.close || !(errno = file->ops.close(file))) {
+ if (file->ref_count > 1) {
+ atomic_fetch_sub(&file->ref_count, 1);
+ } else if (!(errno = file->ops->close(file))) {
atomic_fetch_sub(&file->dnode->ref_count, 1);
file->inode->open_count--;
+ // Prevent dead lock.
+ // This happened when process is terminated while blocking on read.
+ // In that case, the process is still holding the inode lock and it will
+ // never get released.
+ /*
+ * The unlocking should also include ownership check.
+ *
+ * To see why, consider two process both open the same file both with
+ * fd=x.
+ * Process A: busy on reading x
+ * Process B: do nothing with x
+ * Assuming that, after a very short time, process B get terminated
+ * while process A is still busy in it's reading business. By this
+ * design, the inode lock of this file x is get released by B rather
+ * than A. And this will cause a probable race condition on A if other
+ * process is writing to this file later after B exit.
+ */
+ if (mutex_on_hold(&file->inode->lock)) {
+ mutex_unlock_for(&file->inode->lock, pid);
+ }
+ mnt_chillax(file->dnode->mnt);
+
pcache_commit_all(file->inode);
cake_release(file_pile, file);
}
return errno;
}
+int
+vfs_close(struct v_file* file)
+{
+ return vfs_pclose(file, __current->pid);
+}
+
int
vfs_fsync(struct v_file* file)
{
+ int errno;
+ if ((errno = vfs_check_writable(file->dnode))) {
+ return errno;
+ }
+
lock_inode(file->inode);
- int errno = ENOTSUP;
pcache_commit_all(file->inode);
- if (file->ops.sync) {
- errno = file->ops.sync(file->inode);
+
+ errno = ENOTSUP;
+ if (file->ops->sync) {
+ errno = file->ops->sync(file);
}
unlock_inode(file->inode);
struct v_superblock* sb = cake_grab(superblock_pile);
memset(sb, 0, sizeof(*sb));
llist_init_head(&sb->sb_list);
+ sb->i_cache = vzalloc(VFS_HASHTABLE_SIZE * sizeof(struct hbucket));
return sb;
}
void
vfs_sb_free(struct v_superblock* sb)
{
+ vfree(sb->i_cache);
cake_release(superblock_pile, sb);
}
}
struct v_dnode*
-vfs_d_alloc()
+vfs_d_alloc(struct v_dnode* parent, struct hstr* name)
{
struct v_dnode* dnode = cake_grab(dnode_pile);
if (!dnode) {
dnode->ref_count = ATOMIC_VAR_INIT(0);
dnode->name = HHSTR(vzalloc(VFS_NAME_MAXLEN), 0, 0);
+ hstrcpy(&dnode->name, name);
+
+ if (parent) {
+ dnode->super_block = parent->super_block;
+ dnode->mnt = parent->mnt;
+ }
+
lru_use_one(dnode_lru, &dnode->lru);
return dnode;
void
vfs_d_free(struct v_dnode* dnode)
{
- assert(dnode->ref_count == 0);
+ assert(dnode->ref_count == 1);
if (dnode->inode) {
assert(dnode->inode->link_count > 0);
dnode->inode->link_count--;
}
+ vfs_dcache_remove(dnode);
// Make sure the children de-referencing their parent.
// With lru presented, the eviction will be propagated over the entire
// detached subtree eventually
}
struct v_inode*
-vfs_i_alloc(dev_t device_id, uint32_t inode_id)
+vfs_i_find(struct v_superblock* sb, uint32_t i_id)
{
- // 我们这里假设每个文件系统与设备是一一对应（毕竟一个分区不可能有两个不同的文件系统）
- // 而每个文件系统所产生的 v_inode 缓存必须要和其他文件系统产生的区分开来。
- // 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 = (inode_id >> HASHBITS) ^ inode_id;
-
- struct hbucket* slot = &inode_cache[inode_id & HASH_MASK];
+ struct hbucket* slot = &sb->i_cache[i_id & VFS_HASH_MASK];
struct v_inode *pos, *n;
hashtable_bucket_foreach(slot, pos, n, hash_list)
{
- if (pos->id == inode_id) {
- goto done;
+ if (pos->id == i_id) {
+ lru_use_one(inode_lru, &pos->lru);
+ return pos;
}
}
- if (!(pos = cake_grab(inode_pile))) {
+ return NULL;
+}
+
+void
+vfs_i_addhash(struct v_inode* inode)
+{
+ struct hbucket* slot = &inode->sb->i_cache[inode->id & VFS_HASH_MASK];
+
+ hlist_delete(&inode->hash_list);
+ hlist_add(&slot->head, &inode->hash_list);
+}
+
+struct v_inode*
+vfs_i_alloc(struct v_superblock* sb)
+{
+ assert(sb->ops.init_inode);
+
+ struct v_inode* inode;
+ if (!(inode = cake_grab(inode_pile))) {
lru_evict_half(inode_lru);
- if (!(pos = cake_grab(inode_pile))) {
+ if (!(inode = cake_grab(inode_pile))) {
return NULL;
}
}
- memset(pos, 0, sizeof(*pos));
-
- pos->id = inode_id;
+ memset(inode, 0, sizeof(*inode));
+ mutex_init(&inode->lock);
+ llist_init_head(&inode->xattrs);
- mutex_init(&pos->lock);
+ sb->ops.init_inode(sb, inode);
- hlist_add(&slot->head, &pos->hash_list);
+ inode->sb = sb;
+ inode->ctime = clock_unixtime();
+ inode->atime = inode->ctime;
+ inode->mtime = inode->ctime;
done:
- lru_use_one(inode_lru, &pos->lru);
- return pos;
+ lru_use_one(inode_lru, &inode->lru);
+ return inode;
}
void
vfs_i_free(struct v_inode* inode)
{
+ if (inode->pg_cache) {
+ pcache_release(inode->pg_cache);
+ vfree(inode->pg_cache);
+ }
+ inode->ops->sync(inode);
hlist_delete(&inode->hash_list);
cake_release(inode_pile, inode);
}
#define FLOCATE_CREATE_EMPTY 1
-#define DO_STATUS(errno) SYSCALL_ESTATUS(__current->k_status = errno)
-#define DO_STATUS_OR_RETURN(errno) ({ errno < 0 ? DO_STATUS(errno) : errno; })
-
-#define TEST_FD(fd) (fd >= 0 && fd < VFS_MAX_FD)
-
int
-__vfs_getfd(int fd, struct v_fd** fd_s)
+vfs_getfd(int fd, struct v_fd** fd_s)
{
if (TEST_FD(fd) && (*fd_s = __current->fdtable->fds[fd])) {
return 0;
char name_str[VFS_NAME_MAXLEN];
struct hstr name = HSTR(name_str, 0);
int errno;
- if ((errno =
- vfs_walk(__current->cwd, path, fdir, &name, VFS_WALK_PARENT))) {
+
+ name_str[0] = 0;
+ if ((errno = vfs_walk_proc(path, fdir, &name, VFS_WALK_PARENT))) {
return errno;
}
}
struct v_dnode* parent = *fdir;
- struct v_dnode* file_new = vfs_d_alloc();
+ struct v_dnode* file_new = vfs_d_alloc(parent, &name);
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;
-
+ if (!(errno = parent->inode->ops->create(parent->inode, file_new))) {
vfs_dcache_add(parent, file_new);
- llist_append(&parent->children, &file_new->siblings);
+ *file = file_new;
} else {
vfs_d_free(file_new);
}
}
struct v_inode* o_inode = ofile->inode;
- if (!(o_inode->itype & VFS_IFSEQDEV) && !(options & FO_DIRECT)) {
- // XXX Change here accordingly when signature of pcache_r/w changed.
- ofile->ops.read = pcache_read;
- ofile->ops.write = pcache_write;
- }
if (!errno && !(errno = vfs_alloc_fdslot(&fd))) {
struct v_fd* fd_s = vzalloc(sizeof(*fd_s));
{
struct v_fd* fd_s;
int errno = 0;
- if ((errno = __vfs_getfd(fd, &fd_s))) {
+ if ((errno = vfs_getfd(fd, &fd_s))) {
goto done_err;
}
- if (fd_s->file->ref_count > 1) {
- fd_s->file->ref_count--;
- } else if ((errno = vfs_close(fd_s->file))) {
+ if ((errno = vfs_close(fd_s->file))) {
goto done_err;
}
struct v_fd* fd_s;
int errno;
- if ((errno = __vfs_getfd(fd, &fd_s))) {
+ if ((errno = vfs_getfd(fd, &fd_s))) {
goto done;
}
lock_inode(inode);
- if (!(fd_s->file->inode->itype & VFS_IFDIR)) {
+ if (!(inode->itype & VFS_IFDIR)) {
errno = ENOTDIR;
} else {
struct dir_context dctx =
.index = dent->d_offset,
.read_complete_callback =
__vfs_readdir_callback };
+ errno = 1;
if (dent->d_offset == 0) {
- __vfs_readdir_callback(&dctx, vfs_dot.value, vfs_dot.len, 0);
+ __vfs_readdir_callback(&dctx, vfs_dot.value, vfs_dot.len, DT_DIR);
} else if (dent->d_offset == 1) {
- __vfs_readdir_callback(&dctx, vfs_ddot.value, vfs_ddot.len, 0);
+ __vfs_readdir_callback(&dctx, vfs_ddot.value, vfs_ddot.len, DT_DIR);
} else {
dctx.index -= 2;
- if ((errno = fd_s->file->ops.readdir(inode, &dctx))) {
+ if ((errno = fd_s->file->ops->readdir(fd_s->file, &dctx)) != 1) {
unlock_inode(inode);
goto done;
}
}
- errno = 0;
dent->d_offset++;
}
unlock_inode(inode);
done:
- return DO_STATUS(errno);
+ return DO_STATUS_OR_RETURN(errno);
}
__DEFINE_LXSYSCALL3(int, read, int, fd, void*, buf, size_t, count)
{
int errno = 0;
struct v_fd* fd_s;
- if ((errno = __vfs_getfd(fd, &fd_s))) {
+ if ((errno = vfs_getfd(fd, &fd_s))) {
goto done;
}
file->inode->atime = clock_unixtime();
- __SYSCALL_INTERRUPTIBLE(
- { errno = file->ops.read(file->inode, buf, count, file->f_pos); })
+ if ((file->inode->itype & VFS_IFSEQDEV) || (fd_s->flags & FO_DIRECT)) {
+ errno = file->ops->read(file->inode, buf, count, file->f_pos);
+ } else {
+ errno = pcache_read(file->inode, buf, count, file->f_pos);
+ }
if (errno > 0) {
file->f_pos += errno;
{
int errno = 0;
struct v_fd* fd_s;
- if ((errno = __vfs_getfd(fd, &fd_s))) {
+ if ((errno = vfs_getfd(fd, &fd_s))) {
goto done;
}
struct v_file* file = fd_s->file;
+
+ if ((errno = vfs_check_writable(file->dnode))) {
+ goto done;
+ }
+
if ((file->inode->itype & VFS_IFDIR)) {
errno = EISDIR;
goto done;
file->inode->mtime = clock_unixtime();
- __SYSCALL_INTERRUPTIBLE(
- { errno = file->ops.write(file->inode, buf, count, file->f_pos); })
+ if ((file->inode->itype & VFS_IFSEQDEV) || (fd_s->flags & FO_DIRECT)) {
+ errno = file->ops->write(file->inode, buf, count, file->f_pos);
+ } else {
+ errno = pcache_write(file->inode, buf, count, file->f_pos);
+ }
if (errno > 0) {
file->f_pos += errno;
{
int errno = 0;
struct v_fd* fd_s;
- if ((errno = __vfs_getfd(fd, &fd_s))) {
+ if ((errno = vfs_getfd(fd, &fd_s))) {
goto done;
}
struct v_file* file = fd_s->file;
+ if (!file->ops->seek) {
+ errno = ENOTSUP;
+ goto done;
+ }
+
lock_inode(file->inode);
- size_t fpos = file->f_pos;
+ int overflow = 0;
+ int fpos = file->f_pos;
switch (options) {
case FSEEK_CUR:
- fpos = (size_t)((int)file->f_pos + offset);
+ overflow = __builtin_sadd_overflow((int)file->f_pos, offset, &fpos);
break;
case FSEEK_END:
- fpos = (size_t)((int)file->inode->fsize + offset);
+ overflow =
+ __builtin_sadd_overflow((int)file->inode->fsize, offset, &fpos);
break;
case FSEEK_SET:
fpos = offset;
break;
}
- if (!file->ops.seek || !(errno = file->ops.seek(file->inode, fpos))) {
+ if (overflow) {
+ errno = EOVERFLOW;
+ } else if (!(errno = file->ops->seek(file->inode, fpos))) {
file->f_pos = fpos;
}
}
if (depth > 64) {
- return ELOOP;
+ return ENAMETOOLONG;
}
- size_t len = vfs_get_path(dnode->parent, buf, size, depth + 1);
+ size_t len = 0;
+
+ if (dnode->parent != dnode) {
+ len = vfs_get_path(dnode->parent, buf, size, depth + 1);
+ }
if (len >= size) {
return len;
}
+ if (!len || buf[len - 1] != VFS_PATH_DELIM) {
+ buf[len++] = VFS_PATH_DELIM;
+ }
+
size_t cpy_size = MIN(dnode->name.len, size - len);
strncpy(buf + len, dnode->name.value, cpy_size);
len += cpy_size;
- if (len < size) {
- buf[len++] = PATH_DELIM;
- }
-
return len;
}
{
const char* link;
struct v_inode* inode = dnode->inode;
- if (inode->ops.read_symlink) {
+ if (inode->ops->read_symlink) {
lock_inode(inode);
- int errno = inode->ops.read_symlink(inode, &link);
+ int errno = inode->ops->read_symlink(inode, &link);
strncpy(buf, link, size);
unlock_inode(inode);
return 0;
}
+int
+vfs_get_dtype(int itype)
+{
+ switch (itype) {
+ case VFS_IFDIR:
+ return DT_DIR;
+ case VFS_IFSYMLINK:
+ return DT_SYMLINK;
+ default:
+ return DT_PIPE;
+ }
+}
+
__DEFINE_LXSYSCALL3(int, realpathat, int, fd, char*, buf, size_t, size)
{
int errno;
struct v_fd* fd_s;
- if ((errno = __vfs_getfd(fd, &fd_s))) {
+ if ((errno = vfs_getfd(fd, &fd_s))) {
goto done;
}
{
int errno;
struct v_dnode* dnode;
- if (!(errno =
- vfs_walk(__current->cwd, path, &dnode, NULL, VFS_WALK_NOFOLLOW))) {
+ if (!(errno = vfs_walk_proc(path, &dnode, NULL, VFS_WALK_NOFOLLOW))) {
errno = vfs_readlink(dnode, buf, size);
}
{
int errno;
struct v_fd* fd_s;
- if ((errno = __vfs_getfd(dirfd, &fd_s))) {
+ if ((errno = vfs_getfd(dirfd, &fd_s))) {
goto done;
}
{
int errno;
struct v_dnode* dnode;
- if ((errno = vfs_walk(__current->cwd, pathname, &dnode, NULL, 0))) {
+ if ((errno = vfs_walk_proc(pathname, &dnode, NULL, 0))) {
return DO_STATUS(errno);
}
lock_dnode(dnode);
+ if ((errno = vfs_check_writable(dnode))) {
+ goto done;
+ }
+
if ((dnode->super_block->fs->types & FSTYPE_ROFS)) {
errno = EROFS;
goto done;
lock_inode(parent->inode);
if ((dnode->inode->itype & VFS_IFDIR)) {
- errno = parent->inode->ops.rmdir(parent->inode, dnode);
+ errno = parent->inode->ops->rmdir(parent->inode, dnode);
if (!errno) {
vfs_dcache_remove(dnode);
}
__DEFINE_LXSYSCALL1(int, mkdir, const char*, path)
{
int errno = 0;
- struct v_dnode *parent, *dir = vfs_d_alloc();
+ struct v_dnode *parent, *dir;
+ char name_value[VFS_NAME_MAXLEN];
+ struct hstr name = HHSTR(name_value, 0, 0);
- if (!dir) {
- errno = ENOMEM;
+ if ((errno = vfs_walk_proc(path, &parent, &name, VFS_WALK_PARENT))) {
goto done;
}
- if ((errno = vfs_walk(
- __current->cwd, path, &parent, &dir->name, VFS_WALK_PARENT))) {
+ if ((errno = vfs_check_writable(parent))) {
+ goto done;
+ }
+
+ if (!(dir = vfs_d_alloc(parent, &name))) {
+ errno = ENOMEM;
goto done;
}
if ((parent->super_block->fs->types & FSTYPE_ROFS)) {
errno = ENOTSUP;
- } else if (!parent->inode->ops.mkdir) {
+ } else if (!parent->inode->ops->mkdir) {
errno = ENOTSUP;
} else if (!(parent->inode->itype & VFS_IFDIR)) {
errno = ENOTDIR;
- } else if (!(errno = parent->inode->ops.mkdir(parent->inode, dir))) {
- llist_append(&parent->children, &dir->siblings);
+ } else if (!(errno = parent->inode->ops->mkdir(parent->inode, dir))) {
+ vfs_dcache_add(parent, dir);
goto cleanup;
}
int
__vfs_do_unlink(struct v_dnode* dnode)
{
+ int errno;
struct v_inode* inode = dnode->inode;
if (dnode->ref_count > 1) {
return EBUSY;
}
+ if ((errno = vfs_check_writable(dnode))) {
+ return errno;
+ }
+
lock_inode(inode);
- int errno;
if (inode->open_count) {
errno = EBUSY;
} else if (!(inode->itype & VFS_IFDIR)) {
// The underlying unlink implementation should handle
// symlink case
- errno = inode->ops.unlink(inode);
+ errno = inode->ops->unlink(inode);
if (!errno) {
- vfs_dcache_remove(dnode);
vfs_d_free(dnode);
}
} else {
{
int errno;
struct v_dnode* dnode;
- if ((errno = vfs_walk(__current->cwd, pathname, &dnode, NULL, 0))) {
- goto done;
- }
- if ((dnode->super_block->fs->types & FSTYPE_ROFS)) {
- errno = EROFS;
+ if ((errno = vfs_walk_proc(pathname, &dnode, NULL, 0))) {
goto done;
}
{
int errno;
struct v_fd* fd_s;
- if ((errno = __vfs_getfd(fd, &fd_s))) {
+ if ((errno = vfs_getfd(fd, &fd_s))) {
goto done;
}
{
int errno;
struct v_fd* fd_s;
- if (!(errno = __vfs_getfd(fildes, &fd_s))) {
+
+ if (!(errno = vfs_getfd(fildes, &fd_s))) {
errno = vfs_fsync(fd_s->file);
}
int errno;
struct v_fd *oldfd_s, *newfd_s;
- if ((errno = __vfs_getfd(oldfd, &oldfd_s))) {
+ if ((errno = vfs_getfd(oldfd, &oldfd_s))) {
goto done;
}
{
int errno, newfd;
struct v_fd *oldfd_s, *newfd_s;
- if ((errno = __vfs_getfd(oldfd, &oldfd_s))) {
+ if ((errno = vfs_getfd(oldfd, &oldfd_s))) {
goto done;
}
{
int errno;
struct v_dnode* dnode;
- if ((errno = vfs_walk(__current->cwd, pathname, &dnode, NULL, 0))) {
+ if ((errno = vfs_walk_proc(pathname, &dnode, NULL, 0))) {
goto done;
}
- if ((dnode->super_block->fs->types & FSTYPE_ROFS)) {
- errno = EROFS;
+
+ if (errno = vfs_check_writable(dnode)) {
goto done;
}
- if (!dnode->inode->ops.set_symlink) {
+
+ if (!dnode->inode->ops->set_symlink) {
errno = ENOTSUP;
goto done;
}
lock_inode(dnode->inode);
- errno = dnode->inode->ops.set_symlink(dnode->inode, link_target);
+ errno = dnode->inode->ops->set_symlink(dnode->inode, link_target);
unlock_inode(dnode->inode);
return DO_STATUS(errno);
}
+void
+vfs_ref_dnode(struct v_dnode* dnode)
+{
+ atomic_fetch_add(&dnode->ref_count, 1);
+ mnt_mkbusy(dnode->mnt);
+}
+
+void
+vfs_unref_dnode(struct v_dnode* dnode)
+{
+ atomic_fetch_sub(&dnode->ref_count, 1);
+ mnt_chillax(dnode->mnt);
+}
+
int
-__vfs_do_chdir(struct v_dnode* dnode)
+vfs_do_chdir(struct proc_info* proc, struct v_dnode* dnode)
{
int errno = 0;
goto done;
}
- if (__current->cwd) {
- atomic_fetch_add(&__current->cwd->ref_count, 1);
+ if (proc->cwd) {
+ vfs_unref_dnode(proc->cwd);
}
- atomic_fetch_sub(&dnode->ref_count, 1);
- __current->cwd = dnode;
+ vfs_ref_dnode(dnode);
+ proc->cwd = dnode;
unlock_dnode(dnode);
struct v_dnode* dnode;
int errno = 0;
- if ((errno = vfs_walk(__current->cwd, path, &dnode, NULL, 0))) {
+ if ((errno = vfs_walk_proc(path, &dnode, NULL, 0))) {
goto done;
}
- errno = __vfs_do_chdir(dnode);
+ errno = vfs_do_chdir(__current, dnode);
done:
return DO_STATUS(errno);
struct v_fd* fd_s;
int errno = 0;
- if ((errno = __vfs_getfd(fd, &fd_s))) {
+ if ((errno = vfs_getfd(fd, &fd_s))) {
goto done;
}
- errno = __vfs_do_chdir(fd_s->file->dnode);
+ errno = vfs_do_chdir(__current, fd_s->file->dnode);
done:
return DO_STATUS(errno);
size_t len = 0;
if (!__current->cwd) {
- *buf = PATH_DELIM;
+ *buf = VFS_PATH_DELIM;
len = 1;
} else {
len = vfs_get_path(__current->cwd, buf, size, 0);
int
vfs_do_rename(struct v_dnode* current, struct v_dnode* target)
{
+ int errno = 0;
if (current->inode->id == target->inode->id) {
// hard link
return 0;
}
+ if (errno = vfs_check_writable(current)) {
+ return errno;
+ }
+
if (current->ref_count > 1 || target->ref_count > 1) {
return EBUSY;
}
return EXDEV;
}
- int errno = 0;
-
struct v_dnode* oldparent = current->parent;
struct v_dnode* newparent = target->parent;
goto cleanup;
}
- if ((errno = current->inode->ops.rename(current->inode, current, target))) {
+ if ((errno =
+ current->inode->ops->rename(current->inode, current, target))) {
unlock_dnode(target);
goto cleanup;
}
vfs_dcache_rehash(newparent, current);
// detach target
- vfs_dcache_remove(target);
+ vfs_d_free(target);
unlock_dnode(target);
struct hstr name = HSTR(valloc(VFS_NAME_MAXLEN), 0);
int errno = 0;
- if ((errno = vfs_walk(__current->cwd, oldpath, &cur, NULL, 0))) {
+ if ((errno = vfs_walk_proc(oldpath, &cur, NULL, 0))) {
goto done;
}
errno = vfs_walk(target_parent, name.value, &target, NULL, 0);
if (errno == ENOENT) {
- target = vfs_d_alloc();
+ target = vfs_d_alloc(target_parent, &name);
+ vfs_dcache_add(target_parent, target);
} else if (errno) {
goto done;
}
goto done;
}
- hstrcpy(&target->name, &name);
-
- if (!(errno = vfs_do_rename(cur, target))) {
- vfs_d_free(target);
- }
+ errno = vfs_do_rename(cur, target);
done:
vfree(name.value);
return DO_STATUS(errno);
-}
-
-__DEFINE_LXSYSCALL3(int,
- mount,
- const char*,
- source,
- const char*,
- target,
- const char*,
- fstype)
-{
- struct v_dnode *dev, *mnt;
- int errno = 0;
-
- if ((errno = vfs_walk(__current->cwd, source, &dev, NULL, 0))) {
- goto done;
- }
-
- if ((errno = vfs_walk(__current->cwd, target, &mnt, NULL, 0))) {
- goto done;
- }
-
- if (!(dev->inode->itype & VFS_IFVOLDEV)) {
- errno = ENOTDEV;
- goto done;
- }
-
- if (mnt->ref_count > 1) {
- errno = EBUSY;
- goto done;
- }
-
- // FIXME should not touch the underlying fs!
- struct device* device =
- (struct device*)((struct twifs_node*)dev->inode->data)->data;
-
- errno = vfs_mount_at(fstype, device, mnt);
-
-done:
- return DO_STATUS(errno);
-}
-
-__DEFINE_LXSYSCALL1(int, unmount, const char*, target)
-{
- return vfs_unmount(target);
}
\ No newline at end of file
git://scm.lunaixsky.com / lunaix-os.git / blobdiff