X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/ea77b9c3fc7fb9bf9d7f9604fc187c8049212a2a..28c176b668c841a3b7fb093faccf0efa39257603:/lunaix-os/kernel/fs/vfs.c diff --git a/lunaix-os/kernel/fs/vfs.c b/lunaix-os/kernel/fs/vfs.c index df374cd..d4bc56a 100644 --- a/lunaix-os/kernel/fs/vfs.c +++ b/lunaix-os/kernel/fs/vfs.c @@ -40,22 +40,23 @@ we can do similar thing in Lunaix? A block device emulation above the regular file when we mount it on. 10. (device) device number (dev_t) allocation - [good idea] :: composition + [good idea] :: composition (CHECKED) */ #include -#include #include #include #include -#include #include #include #include #include +#include #include +#include + static struct cake_pile* dnode_pile; static struct cake_pile* inode_pile; static struct cake_pile* file_pile; @@ -108,14 +109,14 @@ vfs_init() atomic_fetch_add(&vfs_sysroot->ref_count, 1); } -inline struct hbucket* -__dcache_hash(struct v_dnode* parent, uint32_t* hash) +static inline struct hbucket* +__dcache_hash(struct v_dnode* parent, u32_t* hash) { - uint32_t _hash = *hash; - // 与parent的指针值做加法，来减小碰撞的可能性。 - _hash += (uint32_t)parent; + u32_t _hash = *hash; // 确保低位更加随机 _hash = _hash ^ (_hash >> VFS_HASHBITS); + // 与parent的指针值做加法，来减小碰撞的可能性。 + _hash += (u32_t)__ptr(parent); *hash = _hash; return &dnode_cache[_hash & VFS_HASH_MASK]; } @@ -130,7 +131,7 @@ vfs_dcache_lookup(struct v_dnode* parent, struct hstr* str) return parent->parent; } - uint32_t hash = str->hash; + u32_t hash = str->hash; struct hbucket* slot = __dcache_hash(parent, &hash); struct v_dnode *pos, *n; @@ -199,7 +200,7 @@ vfs_open(struct v_dnode* dnode, struct v_file** file) vfile->ref_count = ATOMIC_VAR_INIT(1); vfile->ops = inode->default_fops; - if ((inode->itype & VFS_IFFILE) && !inode->pg_cache) { + if ((inode->itype & F_MFILE) && !inode->pg_cache) { struct pcache* pcache = vzalloc(sizeof(struct pcache)); pcache_init(pcache); pcache->master = inode; @@ -266,11 +267,11 @@ vfs_pclose(struct v_file* file, pid_t pid) 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. /* + * 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 @@ -300,6 +301,12 @@ vfs_close(struct v_file* file) return vfs_pclose(file, __current->pid); } +void +vfs_free_fd(struct v_fd* fd) +{ + cake_release(fd_pile, fd); +} + int vfs_fsync(struct v_file* file) { @@ -428,12 +435,12 @@ vfs_d_free(struct v_dnode* dnode) vfs_dcache_remove(pos); } - vfree(dnode->name.value); + vfree((void*)dnode->name.value); cake_release(dnode_pile, dnode); } struct v_inode* -vfs_i_find(struct v_superblock* sb, uint32_t i_id) +vfs_i_find(struct v_superblock* sb, u32_t i_id) { struct hbucket* slot = &sb->i_cache[i_id & VFS_HASH_MASK]; struct v_inode *pos, *n; @@ -482,7 +489,6 @@ vfs_i_alloc(struct v_superblock* sb) inode->atime = inode->ctime; inode->mtime = inode->ctime; -done: lru_use_one(inode_lru, &inode->lru); return inode; } @@ -494,7 +500,12 @@ vfs_i_free(struct v_inode* inode) pcache_release(inode->pg_cache); vfree(inode->pg_cache); } - inode->ops->sync(inode); + // we don't need to sync inode. + // If an inode can be free, then it must be properly closed. + // Hence it must be synced already! + if (inode->destruct) { + inode->destruct(inode); + } hlist_delete(&inode->hash_list); cake_release(inode_pile, inode); } @@ -502,6 +513,8 @@ vfs_i_free(struct v_inode* inode) /* ---- System call definition and support ---- */ #define FLOCATE_CREATE_EMPTY 1 +#define FLOCATE_CREATE_ONLY 2 +#define FLOCATE_NOFOLLOW 4 int vfs_getfd(int fd, struct v_fd** fd_s) @@ -520,15 +533,25 @@ __vfs_try_locate_file(const char* path, { char name_str[VFS_NAME_MAXLEN]; struct hstr name = HSTR(name_str, 0); - int errno; + int errno, woption = 0; + + if ((options & FLOCATE_NOFOLLOW)) { + woption |= VFS_WALK_NOFOLLOW; + } name_str[0] = 0; - if ((errno = vfs_walk_proc(path, fdir, &name, VFS_WALK_PARENT))) { + if ((errno = vfs_walk_proc(path, fdir, &name, woption | VFS_WALK_PARENT))) { return errno; } - errno = vfs_walk(*fdir, name.value, file, NULL, 0); - if (errno != ENOENT || !(options & FLOCATE_CREATE_EMPTY)) { + errno = vfs_walk(*fdir, name.value, file, NULL, woption); + + if (errno != ENOENT && (options & FLOCATE_CREATE_ONLY)) { + return EEXIST; + } + + if (errno != ENOENT || + !(options & (FLOCATE_CREATE_EMPTY | FLOCATE_CREATE_ONLY))) { return errno; } @@ -556,21 +579,27 @@ __vfs_try_locate_file(const char* path, int vfs_do_open(const char* path, int options) { - int errno, fd; + int errno, fd, loptions = 0; struct v_dnode *dentry, *file; - struct v_file* ofile = 0; - - errno = __vfs_try_locate_file( - path, &dentry, &file, (options & FO_CREATE) ? FLOCATE_CREATE_EMPTY : 0); + struct v_file* ofile = NULL; - if (errno || (errno = vfs_open(file, &ofile))) { - return errno; + if ((options & FO_CREATE)) { + loptions |= FLOCATE_CREATE_EMPTY; + } else if ((options & FO_NOFOLLOW)) { + loptions |= FLOCATE_NOFOLLOW; } - struct v_inode* o_inode = ofile->inode; + errno = __vfs_try_locate_file(path, &dentry, &file, loptions); if (!errno && !(errno = vfs_alloc_fdslot(&fd))) { - struct v_fd* fd_s = vzalloc(sizeof(*fd_s)); + + if (errno || (errno = vfs_open(file, &ofile))) { + return errno; + } + + struct v_fd* fd_s = cake_grab(fd_pile); + memset(fd_s, 0, sizeof(*fd_s)); + ofile->f_pos = ofile->inode->fsize & -((options & FO_APPEND) != 0); fd_s->file = ofile; fd_s->flags = options; @@ -599,7 +628,7 @@ __DEFINE_LXSYSCALL1(int, close, int, fd) goto done_err; } - vfree(fd_s); + cake_release(fd_pile, fd_s); __current->fdtable->fds[fd] = 0; done_err: @@ -612,13 +641,13 @@ __vfs_readdir_callback(struct dir_context* dctx, const int len, const int dtype) { - struct dirent* dent = (struct dirent*)dctx->cb_data; + struct lx_dirent* dent = (struct lx_dirent*)dctx->cb_data; strncpy(dent->d_name, name, DIRENT_NAME_MAX_LEN); dent->d_nlen = len; dent->d_type = dtype; } -__DEFINE_LXSYSCALL2(int, readdir, int, fd, struct dirent*, dent) +__DEFINE_LXSYSCALL2(int, sys_readdir, int, fd, struct lx_dirent*, dent) { struct v_fd* fd_s; int errno; @@ -631,14 +660,13 @@ __DEFINE_LXSYSCALL2(int, readdir, int, fd, struct dirent*, dent) lock_inode(inode); - if (!(inode->itype & VFS_IFDIR)) { + if ((inode->itype & F_FILE)) { errno = ENOTDIR; } else { - struct dir_context dctx = - (struct dir_context){ .cb_data = dent, - .index = dent->d_offset, - .read_complete_callback = - __vfs_readdir_callback }; + 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); @@ -669,7 +697,7 @@ __DEFINE_LXSYSCALL3(int, read, int, fd, void*, buf, size_t, count) } struct v_file* file = fd_s->file; - if ((file->inode->itype & VFS_IFDIR)) { + if (!(file->inode->itype & F_FILE)) { errno = EISDIR; goto done; } @@ -710,7 +738,7 @@ __DEFINE_LXSYSCALL3(int, write, int, fd, void*, buf, size_t, count) goto done; } - if ((file->inode->itype & VFS_IFDIR)) { + if (!(file->inode->itype & F_FILE)) { errno = EISDIR; goto done; } @@ -758,11 +786,10 @@ __DEFINE_LXSYSCALL3(int, lseek, int, fd, int, offset, int, options) int fpos = file->f_pos; switch (options) { case FSEEK_CUR: - overflow = __builtin_sadd_overflow((int)file->f_pos, offset, &fpos); + overflow = sadd_overflow((int)file->f_pos, offset, &fpos); break; case FSEEK_END: - overflow = - __builtin_sadd_overflow((int)file->inode->fsize, offset, &fpos); + overflow = sadd_overflow((int)file->inode->fsize, offset, &fpos); break; case FSEEK_SET: fpos = offset; @@ -832,13 +859,12 @@ vfs_readlink(struct v_dnode* dnode, char* buf, size_t size) int vfs_get_dtype(int itype) { - switch (itype) { - case VFS_IFDIR: - return DT_DIR; - case VFS_IFSYMLINK: - return DT_SYMLINK; - default: - return DT_PIPE; + if ((itype & VFS_IFSYMLINK) == VFS_IFSYMLINK) { + return DT_SYMLINK; + } else if (!(itype & VFS_IFFILE)) { + return DT_DIR; + } else { + return DT_FILE; } } @@ -876,16 +902,8 @@ __DEFINE_LXSYSCALL3(int, readlink, const char*, path, char*, buf, size_t, size) return DO_STATUS(errno); } -__DEFINE_LXSYSCALL4(int, - readlinkat, - int, - dirfd, - const char*, - pathname, - char*, - buf, - size_t, - size) +__DEFINE_LXSYSCALL4( + int, readlinkat, int, dirfd, const char*, pathname, char*, buf, size_t, size) { int errno; struct v_fd* fd_s; @@ -893,6 +911,8 @@ __DEFINE_LXSYSCALL4(int, goto done; } + pathname = pathname ? pathname : ""; + struct v_dnode* dnode; if (!(errno = vfs_walk( fd_s->file->dnode, pathname, &dnode, NULL, VFS_WALK_NOFOLLOW))) { @@ -954,7 +974,7 @@ __DEFINE_LXSYSCALL1(int, rmdir, const char*, pathname) lock_dnode(parent); lock_inode(parent->inode); - if ((dnode->inode->itype & VFS_IFDIR)) { + if (!(dnode->inode->itype & F_MFILE)) { errno = parent->inode->ops->rmdir(parent->inode, dnode); if (!errno) { vfs_dcache_remove(dnode); @@ -982,6 +1002,11 @@ __DEFINE_LXSYSCALL1(int, mkdir, const char*, path) goto done; } + if (!(errno = vfs_walk(parent, name_value, &dir, NULL, 0))) { + errno = EEXIST; + goto done; + } + if ((errno = vfs_check_writable(parent))) { goto done; } @@ -998,7 +1023,7 @@ __DEFINE_LXSYSCALL1(int, mkdir, const char*, path) errno = ENOTSUP; } else if (!parent->inode->ops->mkdir) { errno = ENOTSUP; - } else if (!(parent->inode->itype & VFS_IFDIR)) { + } else if ((parent->inode->itype & F_FILE)) { errno = ENOTDIR; } else if (!(errno = parent->inode->ops->mkdir(parent->inode, dir))) { vfs_dcache_add(parent, dir); @@ -1032,9 +1057,7 @@ __vfs_do_unlink(struct v_dnode* dnode) if (inode->open_count) { errno = EBUSY; - } else if (!(inode->itype & VFS_IFDIR)) { - // The underlying unlink implementation should handle - // symlink case + } else if ((inode->itype & F_MFILE)) { errno = inode->ops->unlink(inode); if (!errno) { vfs_d_free(dnode); @@ -1087,10 +1110,8 @@ __DEFINE_LXSYSCALL2(int, link, const char*, oldpath, const char*, newpath) errno = __vfs_try_locate_file(oldpath, &dentry, &to_link, 0); if (!errno) { errno = __vfs_try_locate_file( - newpath, &name_dentry, &name_file, FLOCATE_CREATE_EMPTY); + newpath, &name_dentry, &name_file, FLOCATE_CREATE_ONLY); if (!errno) { - errno = EEXIST; - } else if (name_file) { errno = vfs_link(to_link, name_file); } } @@ -1179,50 +1200,58 @@ done: return DO_STATUS(errno); } -__DEFINE_LXSYSCALL2(int, - symlink, - const char*, - pathname, - const char*, - link_target) +__DEFINE_LXSYSCALL2( + int, symlink, const char*, pathname, const char*, link_target) { int errno; - struct v_dnode* dnode; - if ((errno = vfs_walk_proc(pathname, &dnode, NULL, 0))) { + struct v_dnode *dnode, *file; + if ((errno = __vfs_try_locate_file( + pathname, &dnode, &file, FLOCATE_CREATE_ONLY))) { goto done; } - if (errno = vfs_check_writable(dnode)) { + if ((errno = vfs_check_writable(file))) { goto done; } - if (!dnode->inode->ops->set_symlink) { + if (!file->inode->ops->set_symlink) { errno = ENOTSUP; goto done; } - lock_inode(dnode->inode); + lock_inode(file->inode); - errno = dnode->inode->ops->set_symlink(dnode->inode, link_target); + errno = file->inode->ops->set_symlink(file->inode, link_target); - unlock_inode(dnode->inode); + unlock_inode(file->inode); done: return DO_STATUS(errno); } +void +vfs_ref_file(struct v_file* file) +{ + atomic_fetch_add(&file->ref_count, 1); +} + void vfs_ref_dnode(struct v_dnode* dnode) { atomic_fetch_add(&dnode->ref_count, 1); - mnt_mkbusy(dnode->mnt); + + if (dnode->mnt) { + mnt_mkbusy(dnode->mnt); + } } void vfs_unref_dnode(struct v_dnode* dnode) { atomic_fetch_sub(&dnode->ref_count, 1); - mnt_chillax(dnode->mnt); + if (dnode->mnt) { + mnt_chillax(dnode->mnt); + } } int @@ -1232,7 +1261,7 @@ vfs_do_chdir(struct proc_info* proc, struct v_dnode* dnode) lock_dnode(dnode); - if (!(dnode->inode->itype & VFS_IFDIR)) { + if ((dnode->inode->itype & F_FILE)) { errno = ENOTDIR; goto done; } @@ -1259,7 +1288,7 @@ __DEFINE_LXSYSCALL1(int, chdir, const char*, path) goto done; } - errno = vfs_do_chdir(__current, dnode); + errno = vfs_do_chdir((struct proc_info*)__current, dnode); done: return DO_STATUS(errno); @@ -1274,7 +1303,7 @@ __DEFINE_LXSYSCALL1(int, fchdir, int, fd) goto done; } - errno = vfs_do_chdir(__current, fd_s->file->dnode); + errno = vfs_do_chdir((struct proc_info*)__current, fd_s->file->dnode); done: return DO_STATUS(errno); @@ -1302,12 +1331,12 @@ __DEFINE_LXSYSCALL2(char*, getcwd, char*, buf, size_t, size) } } - buf[len + 1] = '\0'; + buf[len] = '\0'; ret_ptr = buf; done: - __current->k_status = errno; + syscall_result(errno); return ret_ptr; } @@ -1320,7 +1349,7 @@ vfs_do_rename(struct v_dnode* current, struct v_dnode* target) return 0; } - if (errno = vfs_check_writable(current)) { + if ((errno = vfs_check_writable(current))) { return errno; } @@ -1404,6 +1433,47 @@ __DEFINE_LXSYSCALL2(int, rename, const char*, oldpath, const char*, newpath) errno = vfs_do_rename(cur, target); done: - vfree(name.value); + vfree((void*)name.value); + return DO_STATUS(errno); +} + +__DEFINE_LXSYSCALL2(int, fstat, int, fd, struct file_stat*, stat) +{ + int errno = 0; + struct v_fd* fds; + + if ((errno = vfs_getfd(fd, &fds))) { + goto done; + } + + struct v_inode* vino = fds->file->inode; + struct device* fdev = vino->sb->dev; + + *stat = (struct file_stat){.st_ino = vino->id, + .st_blocks = vino->lb_usage, + .st_size = vino->fsize, + .mode = vino->itype, + .st_ioblksize = PAGE_SIZE, + .st_blksize = vino->sb->blksize}; + + if (VFS_DEVFILE(vino->itype)) { + struct device* rdev = resolve_device(vino->data); + if (!rdev || rdev->magic != DEV_STRUCT_MAGIC) { + errno = EINVAL; + goto done; + } + + stat->st_rdev = (dev_t){.meta = rdev->ident.fn_grp, + .unique = rdev->ident.unique, + .index = rdev->dev_uid}; + } + + if (fdev) { + stat->st_dev = (dev_t){.meta = fdev->ident.fn_grp, + .unique = fdev->ident.unique, + .index = fdev->dev_uid}; + } + +done: return DO_STATUS(errno); } \ No newline at end of file