X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/ea77b9c3fc7fb9bf9d7f9604fc187c8049212a2a..f8bd95b7a13dfe54d800e2d7ecdb0329f0798289:/lunaix-os/kernel/fs/vfs.c diff --git a/lunaix-os/kernel/fs/vfs.c b/lunaix-os/kernel/fs/vfs.c index df374cd..7959fc3 100644 --- a/lunaix-os/kernel/fs/vfs.c +++ b/lunaix-os/kernel/fs/vfs.c @@ -44,7 +44,6 @@ */ #include -#include #include #include #include @@ -53,9 +52,12 @@ #include #include #include +#include #include +#include + static struct cake_pile* dnode_pile; static struct cake_pile* inode_pile; static struct cake_pile* file_pile; @@ -109,13 +111,13 @@ vfs_init() } inline struct hbucket* -__dcache_hash(struct v_dnode* parent, uint32_t* hash) +__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)parent; *hash = _hash; return &dnode_cache[_hash & VFS_HASH_MASK]; } @@ -130,7 +132,7 @@ 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; @@ -266,11 +268,11 @@ 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 +302,12 @@ 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) { @@ -433,7 +441,7 @@ vfs_d_free(struct v_dnode* 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; @@ -494,7 +502,12 @@ 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 +515,7 @@ vfs_i_free(struct v_inode* inode) /* ---- System call definition and support ---- */ #define FLOCATE_CREATE_EMPTY 1 +#define FLOCATE_CREATE_ONLY 2 int vfs_getfd(int fd, struct v_fd** fd_s) @@ -528,7 +542,13 @@ __vfs_try_locate_file(const char* path, } errno = vfs_walk(*fdir, name.value, file, NULL, 0); - if (errno != ENOENT || !(options & FLOCATE_CREATE_EMPTY)) { + + if (errno != ENOENT && (options & FLOCATE_CREATE_ONLY)) { + return EEXIST; + } + + if (errno != ENOENT || + !(options & (FLOCATE_CREATE_EMPTY | FLOCATE_CREATE_ONLY))) { return errno; } @@ -558,19 +578,20 @@ vfs_do_open(const char* path, int options) { int errno, fd; struct v_dnode *dentry, *file; - struct v_file* ofile = 0; + struct v_file* ofile = NULL; errno = __vfs_try_locate_file( path, &dentry, &file, (options & FO_CREATE) ? FLOCATE_CREATE_EMPTY : 0); - if (errno || (errno = vfs_open(file, &ofile))) { - return errno; - } + if (!errno && !(errno = vfs_alloc_fdslot(&fd))) { - struct v_inode* o_inode = ofile->inode; + 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)); - if (!errno && !(errno = vfs_alloc_fdslot(&fd))) { - struct v_fd* fd_s = vzalloc(sizeof(*fd_s)); ofile->f_pos = ofile->inode->fsize & -((options & FO_APPEND) != 0); fd_s->file = ofile; fd_s->flags = options; @@ -599,7 +620,7 @@ __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 +633,13 @@ __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; @@ -1187,30 +1208,37 @@ __DEFINE_LXSYSCALL2(int, 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) { @@ -1302,7 +1330,7 @@ __DEFINE_LXSYSCALL2(char*, getcwd, char*, buf, size_t, size) } } - buf[len + 1] = '\0'; + buf[len] = '\0'; ret_ptr = buf;