struct hstr vfs_dot = HSTR(".", 1);
struct hstr vfs_empty = HSTR("", 0);
-struct v_superblock*
-vfs_sb_alloc();
-
-void
-vfs_sb_free(struct v_superblock* sb);
-
static int
__vfs_try_evict_dnode(struct lru_node* obj);
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);
+ dnode_lru = lru_new_zone("vfs_dnode", __vfs_try_evict_dnode);
+ inode_lru = lru_new_zone("vfs_inode", __vfs_try_evict_inode);
hstr_rehash(&vfs_ddot, HSTR_FULL_HASH);
hstr_rehash(&vfs_dot, HSTR_FULL_HASH);
return &dnode_cache[_hash & VFS_HASH_MASK];
}
+static inline int
+__sync_inode_nolock(struct v_inode* inode)
+{
+ pcache_commit_all(inode);
+
+ int errno = ENOTSUP;
+ if (inode->ops->sync) {
+ errno = inode->ops->sync(inode);
+ }
+
+ return errno;
+}
+
struct v_dnode*
vfs_dcache_lookup(struct v_dnode* parent, struct hstr* str)
{
struct v_dnode *pos, *n;
hashtable_bucket_foreach(slot, pos, n, hash_list)
{
- if (pos->name.hash == hash) {
+ if (pos->name.hash == hash && pos->parent == parent) {
return pos;
}
}
vfile->ref_count = ATOMIC_VAR_INIT(1);
vfile->ops = inode->default_fops;
- if ((inode->itype & F_MFILE) && !inode->pg_cache) {
+ if (check_file_node(inode) && !inode->pg_cache) {
struct pcache* pcache = vzalloc(sizeof(struct pcache));
pcache_init(pcache);
pcache->master = inode;
llist_delete(&assign_to->aka_list);
assign_to->inode->link_count--;
}
+
llist_append(&inode->aka_dnodes, &assign_to->aka_list);
assign_to->inode = inode;
inode->link_count++;
int
vfs_pclose(struct v_file* file, pid_t pid)
{
+ struct v_inode* inode;
int errno = 0;
+
+ inode = file->inode;
+
+ /*
+ * 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.
+ */
+
+ mutex_unlock_for(&inode->lock, pid);
+
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);
+ return 0;
+ }
+
+ if ((errno = file->ops->close(file))) {
+ goto done;
+ }
+
+ atomic_fetch_sub(&file->dnode->ref_count, 1);
+ mnt_chillax(file->dnode->mnt);
+ cake_release(file_pile, file);
+
+ /*
+ if the current inode is not being locked by other
+ threads that does not share same open context,
+ then we can try to do sync opportunistically
+ */
+ if (mutex_on_hold(&inode->lock)) {
+ goto done;
+ }
+
+ lock_inode(inode);
- pcache_commit_all(file->inode);
- cake_release(file_pile, file);
+ pcache_commit_all(inode);
+ inode->open_count--;
+
+ if (!inode->open_count) {
+ __sync_inode_nolock(inode);
}
+
+ unlock_inode(inode);
+
+done:
return errno;
}
cake_release(fd_pile, fd);
}
+int
+vfs_isync(struct v_inode* inode)
+{
+ lock_inode(inode);
+
+ int errno = __sync_inode_nolock(inode);
+
+ unlock_inode(inode);
+
+ return errno;
+}
+
int
vfs_fsync(struct v_file* file)
{
return errno;
}
- lock_inode(file->inode);
-
- pcache_commit_all(file->inode);
-
- errno = ENOTSUP;
- if (file->ops->sync) {
- errno = file->ops->sync(file);
- }
-
- unlock_inode(file->inode);
-
- return errno;
+ return vfs_isync(file->inode);
}
int
memset(sb, 0, sizeof(*sb));
llist_init_head(&sb->sb_list);
sb->i_cache = vzalloc(VFS_HASHTABLE_SIZE * sizeof(struct hbucket));
+ sb->ref_count = 1;
return sb;
}
+void
+vfs_sb_ref(struct v_superblock* sb)
+{
+ sb->ref_count++;
+}
+
void
vfs_sb_free(struct v_superblock* sb)
{
+ assert(sb->ref_count);
+
+ sb->ref_count--;
+ if (sb->ref_count) {
+ return;
+ }
+
+ if (sb->ops.release) {
+ sb->ops.release(sb);
+ }
+
vfree(sb->i_cache);
cake_release(superblock_pile, sb);
}
hstrcpy(&dnode->name, name);
if (parent) {
- dnode->super_block = parent->super_block;
+ vfs_d_assign_sb(dnode, parent->super_block);
dnode->mnt = parent->mnt;
}
vfs_dcache_remove(pos);
}
+ if (dnode->destruct) {
+ dnode->destruct(dnode);
+ }
+
+ vfs_sb_free(dnode->super_block);
vfree((void*)dnode->name.value);
cake_release(dnode_pile, dnode);
}
sb->ops.init_inode(sb, inode);
- inode->sb = sb;
inode->ctime = clock_unixtime();
inode->atime = inode->ctime;
inode->mtime = inode->ctime;
+ vfs_i_assign_sb(inode, sb);
lru_use_one(inode_lru, &inode->lru);
return inode;
}
if (inode->destruct) {
inode->destruct(inode);
}
+
+ vfs_sb_free(inode->sb);
hlist_delete(&inode->hash_list);
cake_release(inode_pile, inode);
}
/* ---- System call definition and support ---- */
-#define FLOCATE_CREATE_EMPTY 1
-#define FLOCATE_CREATE_ONLY 2
-#define FLOCATE_NOFOLLOW 4
+// make a new name when not exists
+#define FLOC_MAYBE_MKNAME 1
+
+// name must be non-exist and made.
+#define FLOC_MKNAME 2
+
+// no follow symlink
+#define FLOC_NOFOLLOW 4
int
vfs_getfd(int fd, struct v_fd** fd_s)
return EBADF;
}
-int
+static int
+__vfs_mknod(struct v_inode* parent, struct v_dnode* dnode,
+ unsigned int itype, dev_t* dev)
+{
+ int errno;
+
+ errno = parent->ops->create(parent, dnode, itype);
+ if (errno) {
+ return errno;
+ }
+
+ return 0;
+}
+
+struct file_locator {
+ struct v_dnode* dir;
+ struct v_dnode* file;
+ bool fresh;
+};
+
+/**
+ * @brief unlock the file locator (floc) if possible.
+ * If the file to be located if not exists, and
+ * any FLOC_*MKNAME flag is set, then the parent
+ * dnode will be locked until the file has been properly
+ * finalised by subsequent logic.
+ *
+ * @param floc
+ */
+static inline void
+__floc_try_unlock(struct file_locator* floc)
+{
+ if (floc->fresh) {
+ assert(floc->dir);
+ unlock_dnode(floc->dir);
+ }
+}
+
+static int
__vfs_try_locate_file(const char* path,
- struct v_dnode** fdir,
- struct v_dnode** file,
+ struct file_locator* floc,
int options)
{
char name_str[VFS_NAME_MAXLEN];
+ struct v_dnode *fdir, *file;
struct hstr name = HSTR(name_str, 0);
int errno, woption = 0;
- if ((options & FLOCATE_NOFOLLOW)) {
+ if ((options & FLOC_NOFOLLOW)) {
woption |= VFS_WALK_NOFOLLOW;
+ options &= ~FLOC_NOFOLLOW;
}
+ floc->fresh = false;
name_str[0] = 0;
- if ((errno = vfs_walk_proc(path, fdir, &name, woption | VFS_WALK_PARENT))) {
+ errno = vfs_walk_proc(path, &fdir, &name, woption | VFS_WALK_PARENT);
+ if (errno) {
return errno;
}
- errno = vfs_walk(*fdir, name.value, file, NULL, woption);
+ errno = vfs_walk(fdir, name.value, &file, NULL, woption);
- if (errno != ENOENT && (options & FLOCATE_CREATE_ONLY)) {
- return EEXIST;
+ if (errno && errno != ENOENT) {
+ goto done;
+ }
+
+ if (!errno) {
+ if ((options & FLOC_MKNAME)) {
+ errno = EEXIST;
+ }
+ goto done;
}
- if (errno != ENOENT ||
- !(options & (FLOCATE_CREATE_EMPTY | FLOCATE_CREATE_ONLY))) {
- return errno;
+ // errno == ENOENT
+ if (!options) {
+ goto done;
+ }
+
+ errno = vfs_check_writable(fdir);
+ if (errno) {
+ goto done;
}
- struct v_dnode* parent = *fdir;
- struct v_dnode* file_new = vfs_d_alloc(parent, &name);
+ floc->fresh = true;
+
+ file = vfs_d_alloc(fdir, &name);
- if (!file_new) {
+ if (!file) {
return ENOMEM;
}
- lock_dnode(parent);
+ lock_dnode(fdir);
- if (!(errno = parent->inode->ops->create(parent->inode, file_new))) {
- vfs_dcache_add(parent, file_new);
- *file = file_new;
- } else {
- vfs_d_free(file_new);
- }
+ vfs_dcache_add(fdir, file);
- unlock_dnode(parent);
+done:
+ floc->dir = fdir;
+ floc->file = file;
return errno;
}
int errno, fd, loptions = 0;
struct v_dnode *dentry, *file;
struct v_file* ofile = NULL;
+ struct file_locator floc;
+ struct v_inode* inode;
if ((options & FO_CREATE)) {
- loptions |= FLOCATE_CREATE_EMPTY;
+ loptions |= FLOC_MAYBE_MKNAME;
} else if ((options & FO_NOFOLLOW)) {
- loptions |= FLOCATE_NOFOLLOW;
+ loptions |= FLOC_NOFOLLOW;
}
- errno = __vfs_try_locate_file(path, &dentry, &file, loptions);
+ errno = __vfs_try_locate_file(path, &floc, loptions);
+
+ if (errno || (errno = vfs_alloc_fdslot(&fd))) {
+ return errno;
+ }
- if (!errno && !(errno = vfs_alloc_fdslot(&fd))) {
+ file = floc.file;
+ dentry = floc.dir;
- if (errno || (errno = vfs_open(file, &ofile))) {
+ if (floc.fresh) {
+ errno = __vfs_mknod(dentry->inode, file, VFS_IFFILE, NULL);
+ if (errno) {
+ vfs_d_free(file);
+ __floc_try_unlock(&floc);
return errno;
}
- struct v_fd* fd_s = cake_grab(fd_pile);
- memset(fd_s, 0, sizeof(*fd_s));
+ __floc_try_unlock(&floc);
+ }
+
- ofile->f_pos = ofile->inode->fsize & -((options & FO_APPEND) != 0);
- fd_s->file = ofile;
- fd_s->flags = options;
- __current->fdtable->fds[fd] = fd_s;
- return fd;
+ if ((errno = vfs_open(file, &ofile))) {
+ return errno;
}
- return errno;
+ inode = ofile->inode;
+ lock_inode(inode);
+
+ struct v_fd* fd_s = cake_grab(fd_pile);
+ memset(fd_s, 0, sizeof(*fd_s));
+
+ if ((options & O_TRUNC)) {
+ file->inode->fsize = 0;
+ }
+
+ if (vfs_get_dtype(inode->itype) == DT_DIR) {
+ ofile->f_pos = 0;
+ }
+
+ fd_s->file = ofile;
+ fd_s->flags = options;
+ __current->fdtable->fds[fd] = fd_s;
+
+ unlock_inode(inode);
+
+ return fd;
}
__DEFINE_LXSYSCALL2(int, open, const char*, path, int, options)
const int dtype)
{
struct lx_dirent* dent = (struct lx_dirent*)dctx->cb_data;
- strncpy(dent->d_name, name, DIRENT_NAME_MAX_LEN);
+ strncpy(dent->d_name, name, MIN(len, DIRENT_NAME_MAX_LEN));
dent->d_nlen = len;
dent->d_type = dtype;
}
lock_inode(inode);
- if ((inode->itype & F_FILE)) {
+ if (!check_directory_node(inode)) {
errno = ENOTDIR;
- } else {
- struct dir_context dctx = (struct dir_context){
- .cb_data = dent,
- .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, DT_DIR);
- } else if (dent->d_offset == 1) {
- __vfs_readdir_callback(&dctx, vfs_ddot.value, vfs_ddot.len, DT_DIR);
- } else {
- dctx.index -= 2;
- if ((errno = fd_s->file->ops->readdir(fd_s->file, &dctx)) != 1) {
- unlock_inode(inode);
- goto done;
- }
- }
- dent->d_offset++;
+ goto unlock;
+ }
+
+ struct dir_context dctx = (struct dir_context) {
+ .cb_data = dent,
+ .read_complete_callback = __vfs_readdir_callback
+ };
+
+ if ((errno = fd_s->file->ops->readdir(fd_s->file, &dctx)) != 1) {
+ goto unlock;
}
+ dent->d_offset++;
+ fd_s->file->f_pos++;
+unlock:
unlock_inode(inode);
done:
}
struct v_file* file = fd_s->file;
- if (!(file->inode->itype & F_FILE)) {
+ if (check_directory_node(file->inode)) {
errno = EISDIR;
goto done;
}
file->inode->atime = clock_unixtime();
- if ((file->inode->itype & VFS_IFSEQDEV) || (fd_s->flags & FO_DIRECT)) {
+ if (check_seqdev_node(file->inode) || (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);
goto done;
}
+ struct v_inode* inode;
struct v_file* file = fd_s->file;
if ((errno = vfs_check_writable(file->dnode))) {
goto done;
}
- if (!(file->inode->itype & F_FILE)) {
+ if (check_directory_node(file->inode)) {
errno = EISDIR;
goto done;
}
- lock_inode(file->inode);
+ inode = file->inode;
+ lock_inode(inode);
- file->inode->mtime = clock_unixtime();
+ inode->mtime = clock_unixtime();
+ if ((fd_s->flags & O_APPEND)) {
+ file->f_pos = inode->fsize;
+ }
- if ((file->inode->itype & VFS_IFSEQDEV) || (fd_s->flags & FO_DIRECT)) {
- errno = file->ops->write(file->inode, buf, count, file->f_pos);
+ if (check_seqdev_node(inode) || (fd_s->flags & FO_DIRECT)) {
+ errno = file->ops->write(inode, buf, count, file->f_pos);
} else {
- errno = pcache_write(file->inode, buf, count, file->f_pos);
+ errno = pcache_write(inode, buf, count, file->f_pos);
}
if (errno > 0) {
file->f_pos += errno;
- unlock_inode(file->inode);
+ inode->fsize = MAX(inode->fsize, file->f_pos);
+
+ unlock_inode(inode);
return errno;
}
- unlock_inode(file->inode);
+ unlock_inode(inode);
done:
return DO_STATUS(errno);
}
struct v_file* file = fd_s->file;
+ struct v_inode* inode = file->inode;
if (!file->ops->seek) {
errno = ENOTSUP;
goto done;
}
- lock_inode(file->inode);
+ lock_inode(inode);
int overflow = 0;
int fpos = file->f_pos;
+
+ if (vfs_get_dtype(inode->itype) == DT_DIR) {
+ options = (options != FSEEK_END) ? options : FSEEK_SET;
+ }
+
switch (options) {
case FSEEK_CUR:
- overflow = sadd_overflow((int)file->f_pos, offset, &fpos);
+ overflow = sadd_of((int)file->f_pos, offset, &fpos);
break;
case FSEEK_END:
- overflow = sadd_overflow((int)file->inode->fsize, offset, &fpos);
+ overflow = sadd_of((int)inode->fsize, offset, &fpos);
break;
case FSEEK_SET:
fpos = offset;
break;
}
+
if (overflow) {
errno = EOVERFLOW;
- } else if (!(errno = file->ops->seek(file->inode, fpos))) {
- file->f_pos = fpos;
+ }
+ else {
+ errno = file->ops->seek(file, fpos);
}
- unlock_inode(file->inode);
+ unlock_inode(inode);
done:
return DO_STATUS(errno);
{
const char* link;
struct v_inode* inode = dnode->inode;
- if (inode->ops->read_symlink) {
- lock_inode(inode);
- int errno = inode->ops->read_symlink(inode, &link);
- strncpy(buf, link, size);
+ if (!check_symlink_node(inode)) {
+ return EINVAL;
+ }
- unlock_inode(inode);
- return errno;
+ if (!inode->ops->read_symlink) {
+ return ENOTSUP;
}
- return 0;
+
+ lock_inode(inode);
+
+ int errno = inode->ops->read_symlink(inode, &link);
+ if (errno >= 0) {
+ strncpy(buf, link, MIN(size, (size_t)errno));
+ }
+
+ unlock_inode(inode);
+ return errno;
}
int
vfs_get_dtype(int itype)
{
- if ((itype & VFS_IFSYMLINK) == VFS_IFSYMLINK) {
- return DT_SYMLINK;
- } else if (!(itype & VFS_IFFILE)) {
- return DT_DIR;
- } else {
- return DT_FILE;
+ int dtype = DT_FILE;
+ if (check_itype(itype, VFS_IFSYMLINK)) {
+ dtype |= DT_SYMLINK;
}
+
+ if (check_itype(itype, VFS_IFDIR)) {
+ dtype |= DT_DIR;
+ return dtype;
+ }
+
+ // TODO other types
+
+ return dtype;
}
__DEFINE_LXSYSCALL3(int, realpathat, int, fd, char*, buf, size_t, size)
lock_dnode(parent);
lock_inode(parent->inode);
- if (!(dnode->inode->itype & F_MFILE)) {
+ if (check_directory_node(dnode->inode)) {
errno = parent->inode->ops->rmdir(parent->inode, dnode);
if (!errno) {
vfs_dcache_remove(dnode);
goto done;
}
+ struct v_inode* inode = parent->inode;
+
lock_dnode(parent);
- lock_inode(parent->inode);
+ lock_inode(inode);
if ((parent->super_block->fs->types & FSTYPE_ROFS)) {
errno = ENOTSUP;
- } else if (!parent->inode->ops->mkdir) {
+ } else if (!inode->ops->mkdir) {
errno = ENOTSUP;
- } else if ((parent->inode->itype & F_FILE)) {
+ } else if (!check_directory_node(inode)) {
errno = ENOTDIR;
- } else if (!(errno = parent->inode->ops->mkdir(parent->inode, dir))) {
+ } else if (!(errno = inode->ops->mkdir(inode, dir))) {
vfs_dcache_add(parent, dir);
goto cleanup;
}
vfs_d_free(dir);
cleanup:
- unlock_inode(parent->inode);
+ unlock_inode(inode);
unlock_dnode(parent);
done:
return DO_STATUS(errno);
if (inode->open_count) {
errno = EBUSY;
- } else if ((inode->itype & F_MFILE)) {
- errno = inode->ops->unlink(inode);
+ } else if (!check_directory_node(inode)) {
+ errno = inode->ops->unlink(inode, dnode);
if (!errno) {
vfs_d_free(dnode);
}
__DEFINE_LXSYSCALL2(int, link, const char*, oldpath, const char*, newpath)
{
int errno;
- struct v_dnode *dentry, *to_link, *name_dentry, *name_file;
+ struct file_locator floc;
+ struct v_dnode *to_link, *name_file;
- errno = __vfs_try_locate_file(oldpath, &dentry, &to_link, 0);
+ errno = __vfs_try_locate_file(oldpath, &floc, 0);
+ if (errno) {
+ goto done;
+ }
+
+ __floc_try_unlock(&floc);
+
+ to_link = floc.file;
+ errno = __vfs_try_locate_file(newpath, &floc, FLOC_MKNAME);
if (!errno) {
- errno = __vfs_try_locate_file(
- newpath, &name_dentry, &name_file, FLOCATE_CREATE_ONLY);
- if (!errno) {
- errno = vfs_link(to_link, name_file);
- }
+ goto done;
+ }
+
+ name_file = floc.file;
+ errno = vfs_link(to_link, name_file);
+ if (errno) {
+ vfs_d_free(name_file);
}
+
+done:
+ __floc_try_unlock(&floc);
return DO_STATUS(errno);
}
int, symlink, const char*, pathname, const char*, link_target)
{
int errno;
- struct v_dnode *dnode, *file;
- if ((errno = __vfs_try_locate_file(
- pathname, &dnode, &file, FLOCATE_CREATE_ONLY))) {
+ struct file_locator floc;
+ struct v_dnode *file;
+ struct v_inode *f_ino;
+
+ errno = __vfs_try_locate_file(pathname, &floc, FLOC_MKNAME);
+ if (errno) {
goto done;
}
- if ((errno = vfs_check_writable(file))) {
+ file = floc.file;
+ errno = __vfs_mknod(floc.dir->inode, file, VFS_IFSYMLINK, NULL);
+ if (errno) {
+ vfs_d_free(file);
goto done;
}
- if (!file->inode->ops->set_symlink) {
+ f_ino = file->inode;
+
+ assert(f_ino);
+
+ errno = vfs_check_writable(file);
+ if (errno) {
+ goto done;
+ }
+
+ if (!f_ino->ops->set_symlink) {
errno = ENOTSUP;
goto done;
}
- lock_inode(file->inode);
+ lock_inode(f_ino);
- errno = file->inode->ops->set_symlink(file->inode, link_target);
+ errno = f_ino->ops->set_symlink(f_ino, link_target);
- unlock_inode(file->inode);
+ unlock_inode(f_ino);
done:
+ __floc_try_unlock(&floc);
return DO_STATUS(errno);
}
lock_dnode(dnode);
- if ((dnode->inode->itype & F_FILE)) {
+ if (!check_directory_node(dnode->inode)) {
errno = ENOTDIR;
goto done;
}
.st_ioblksize = PAGE_SIZE,
.st_blksize = vino->sb->blksize};
- if (VFS_DEVFILE(vino->itype)) {
+ if (check_device_node(vino)) {
struct device* rdev = resolve_device(vino->data);
- if (!rdev || rdev->magic != DEV_STRUCT_MAGIC) {
+ if (!rdev) {
errno = EINVAL;
goto done;
}
stat->st_rdev = (dev_t){.meta = rdev->ident.fn_grp,
.unique = rdev->ident.unique,
- .index = rdev->dev_uid};
+ .index = dev_uid(rdev) };
}
if (fdev) {
stat->st_dev = (dev_t){.meta = fdev->ident.fn_grp,
.unique = fdev->ident.unique,
- .index = fdev->dev_uid};
+ .index = dev_uid(fdev) };
}
done:
git://scm.lunaixsky.com / lunaix-os.git / blobdiff