X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/ea77b9c3fc7fb9bf9d7f9604fc187c8049212a2a..0fd474df7001837bde53da0e42e83081827c9641:/lunaix-os/kernel/fs/vfs.c diff --git a/lunaix-os/kernel/fs/vfs.c b/lunaix-os/kernel/fs/vfs.c index df374cd..32014d3 100644 --- a/lunaix-os/kernel/fs/vfs.c +++ b/lunaix-os/kernel/fs/vfs.c @@ -40,30 +40,33 @@ 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 + +#define INODE_ACCESSED 0 +#define INODE_MODIFY 1 + 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; -struct v_dnode* vfs_sysroot; -static struct hbucket* dnode_cache; +struct v_dnode* vfs_sysroot = NULL; struct lru_zone *dnode_lru, *inode_lru; @@ -71,12 +74,6 @@ struct hstr vfs_ddot = HSTR("..", 2); 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); @@ -94,10 +91,8 @@ vfs_init() superblock_pile = cake_new_pile("sb_cache", sizeof(struct v_superblock), 1, 0); - 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); @@ -105,19 +100,36 @@ vfs_init() // 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); + + vfs_ref_dnode(vfs_sysroot); } -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; - // 确保低位更加随机 + struct hbucket* d_cache; + u32_t _hash; + + d_cache = parent->super_block->d_cache; + _hash = *hash; _hash = _hash ^ (_hash >> VFS_HASHBITS); + _hash += (u32_t)__ptr(parent); + *hash = _hash; - return &dnode_cache[_hash & VFS_HASH_MASK]; + return &d_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* @@ -130,25 +142,39 @@ 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; hashtable_bucket_foreach(slot, pos, n, hash_list) { - if (pos->name.hash == hash) { + if (pos->name.hash == hash && pos->parent == parent) { return pos; } } return NULL; } +static void +__vfs_touch_inode(struct v_inode* inode, const int type) +{ + if (type == INODE_MODIFY) { + inode->mtime = clock_unixtime(); + } + + else if (type == INODE_ACCESSED) { + inode->atime = clock_unixtime(); + } + + lru_use_one(inode_lru, &inode->lru); +} + void vfs_dcache_add(struct v_dnode* parent, struct v_dnode* dnode) { assert(parent); - atomic_fetch_add(&dnode->ref_count, 1); + dnode->ref_count = 1; dnode->parent = parent; llist_append(&parent->children, &dnode->siblings); @@ -167,7 +193,7 @@ vfs_dcache_remove(struct v_dnode* dnode) hlist_delete(&dnode->hash_list); dnode->parent = NULL; - atomic_fetch_sub(&dnode->ref_count, 1); + dnode->ref_count = 0; } void @@ -183,12 +209,12 @@ vfs_dcache_rehash(struct v_dnode* new_parent, struct v_dnode* dnode) int vfs_open(struct v_dnode* dnode, struct v_file** file) { - if (!dnode->inode || !dnode->inode->ops->open) { + struct v_inode* inode = dnode->inode; + + if (!inode || !inode->ops->open) { return ENOTSUP; } - struct v_inode* inode = dnode->inode; - lock_inode(inode); struct v_file* vfile = cake_grab(file_pile); @@ -196,10 +222,10 @@ vfs_open(struct v_dnode* dnode, struct v_file** file) vfile->dnode = dnode; vfile->inode = inode; - vfile->ref_count = ATOMIC_VAR_INIT(1); + vfile->ref_count = 1; vfile->ops = inode->default_fops; - if ((inode->itype & VFS_IFFILE) && !inode->pg_cache) { + if (check_regfile_node(inode) && !inode->pg_cache) { struct pcache* pcache = vzalloc(sizeof(struct pcache)); pcache_init(pcache); pcache->master = inode; @@ -210,9 +236,8 @@ vfs_open(struct v_dnode* dnode, struct v_file** file) if (errno) { cake_release(file_pile, vfile); } else { - atomic_fetch_add(&dnode->ref_count, 1); + vfs_ref_dnode(dnode); inode->open_count++; - mnt_mkbusy(dnode->mnt); *file = vfile; } @@ -229,6 +254,7 @@ vfs_assign_inode(struct v_dnode* assign_to, struct v_inode* 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++; @@ -259,38 +285,64 @@ vfs_link(struct v_dnode* to_link, struct v_dnode* name) int vfs_pclose(struct v_file* file, pid_t pid) { + struct v_inode* inode; int errno = 0; - 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); + 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 (vfs_check_duped_file(file)) { + vfs_unref_file(file); + return 0; + } + + if ((errno = file->ops->close(file))) { + goto done; } + + vfs_unref_dnode(file->dnode); + 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(inode); + inode->open_count--; + + if (!inode->open_count) { + __sync_inode_nolock(inode); + } + + unlock_inode(inode); + +done: return errno; } @@ -300,6 +352,24 @@ 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_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) { @@ -308,18 +378,7 @@ 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 @@ -340,14 +399,37 @@ vfs_sb_alloc() 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)); + sb->d_cache = vzalloc(VFS_HASHTABLE_SIZE * sizeof(struct hbucket)); + + sb->ref_count = 1; return sb; } void -vfs_sb_free(struct v_superblock* sb) +vfs_sb_ref(struct v_superblock* sb) +{ + sb->ref_count++; +} + +void +vfs_sb_unref(struct v_superblock* sb) { + assert(sb->ref_count); + + sb->ref_count--; + if (likely(sb->ref_count)) { + return; + } + + if (sb->ops.release) { + sb->ops.release(sb); + } + vfree(sb->i_cache); + vfree(sb->d_cache); + cake_release(superblock_pile, sb); } @@ -393,13 +475,12 @@ vfs_d_alloc(struct v_dnode* parent, struct hstr* name) llist_init_head(&dnode->aka_list); mutex_init(&dnode->lock); - 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; + vfs_d_assign_sb(dnode, parent->super_block); dnode->mnt = parent->mnt; } @@ -428,12 +509,17 @@ vfs_d_free(struct v_dnode* dnode) vfs_dcache_remove(pos); } - vfree(dnode->name.value); + if (dnode->destruct) { + dnode->destruct(dnode); + } + + vfs_sb_unref(dnode->super_block); + 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; @@ -477,12 +563,11 @@ vfs_i_alloc(struct v_superblock* sb) sb->ops.init_inode(sb, inode); - inode->sb = sb; inode->ctime = clock_unixtime(); inode->atime = inode->ctime; inode->mtime = inode->ctime; -done: + vfs_i_assign_sb(inode, sb); lru_use_one(inode_lru, &inode->lru); return inode; } @@ -494,14 +579,28 @@ 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); + } + + vfs_sb_unref(inode->sb); hlist_delete(&inode->hash_list); cake_release(inode_pile, inode); } /* ---- System call definition and support ---- */ -#define FLOCATE_CREATE_EMPTY 1 +// 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) @@ -512,73 +611,194 @@ 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; + int errno, woption = 0; + + 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, 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, 0); - if (errno != ENOENT || !(options & FLOCATE_CREATE_EMPTY)) { - return errno; + errno = vfs_walk(fdir, name.value, &file, NULL, woption); + + if (errno && errno != ENOENT) { + goto done; + } + + if (!errno) { + if ((options & FLOC_MKNAME)) { + errno = EEXIST; + } + goto done; + } + + // 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; } + +static bool +__check_unlinkable(struct v_dnode* dnode) +{ + int acl; + bool wr_self, wr_parent; + struct v_dnode* parent; + + parent = dnode->parent; + acl = dnode->inode->acl; + + wr_self = check_allow_write(dnode->inode); + wr_parent = check_allow_write(parent->inode); + + if (!fsacl_test(acl, svtx)) { + return wr_self; + } + + if (current_euid() == dnode->inode->uid) { + return true; + } + + return wr_self && wr_parent; +} + 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; + struct v_file* ofile = NULL; + struct file_locator floc; + struct v_inode* inode; - errno = __vfs_try_locate_file( - path, &dentry, &file, (options & FO_CREATE) ? FLOCATE_CREATE_EMPTY : 0); + if ((options & FO_CREATE)) { + loptions |= FLOC_MAYBE_MKNAME; + } else if ((options & FO_NOFOLLOW)) { + loptions |= FLOC_NOFOLLOW; + } + + errno = __vfs_try_locate_file(path, &floc, loptions); - if (errno || (errno = vfs_open(file, &ofile))) { + if (errno || (errno = vfs_alloc_fdslot(&fd))) { return errno; } - struct v_inode* o_inode = ofile->inode; + file = floc.file; + dentry = floc.dir; + + if (floc.fresh) { + errno = __vfs_mknod(dentry->inode, file, VFS_IFFILE, NULL); + if (errno) { + vfs_d_free(file); + __floc_try_unlock(&floc); + return errno; + } - 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; - __current->fdtable->fds[fd] = fd_s; - return fd; + __floc_try_unlock(&floc); } - return errno; + + if ((errno = vfs_open(file, &ofile))) { + 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) @@ -599,7 +819,7 @@ __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 +832,13 @@ __vfs_readdir_callback(struct dir_context* dctx, const int len, const int dtype) { - struct dirent* dent = (struct dirent*)dctx->cb_data; - strncpy(dent->d_name, name, DIRENT_NAME_MAX_LEN); + struct lx_dirent* dent = (struct lx_dirent*)dctx->cb_data; + strncpy(dent->d_name, name, MIN(len, 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; @@ -631,29 +851,28 @@ __DEFINE_LXSYSCALL2(int, readdir, int, fd, struct dirent*, dent) lock_inode(inode); - if (!(inode->itype & VFS_IFDIR)) { + 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; + } + + if (!check_allow_read(inode)) { + errno = EPERM; + 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: @@ -664,33 +883,41 @@ __DEFINE_LXSYSCALL3(int, read, int, fd, void*, buf, size_t, count) { int errno = 0; struct v_fd* fd_s; + struct v_inode* inode; + if ((errno = vfs_getfd(fd, &fd_s))) { goto done; } struct v_file* file = fd_s->file; - if ((file->inode->itype & VFS_IFDIR)) { + if (check_directory_node(file->inode)) { errno = EISDIR; goto done; } - lock_inode(file->inode); + if (!check_allow_read(file->inode)) { + errno = EPERM; + goto done; + } + + inode = file->inode; + lock_inode(inode); - file->inode->atime = clock_unixtime(); + __vfs_touch_inode(inode, INODE_ACCESSED); - if ((file->inode->itype & VFS_IFSEQDEV) || (fd_s->flags & FO_DIRECT)) { - errno = file->ops->read(file->inode, buf, count, file->f_pos); + if (check_seqdev_node(inode) || (fd_s->flags & FO_DIRECT)) { + errno = file->ops->read(inode, buf, count, file->f_pos); } else { - errno = pcache_read(file->inode, buf, count, file->f_pos); + errno = pcache_read(inode, buf, count, file->f_pos); } if (errno > 0) { file->f_pos += errno; - unlock_inode(file->inode); + unlock_inode(inode); return errno; } - unlock_inode(file->inode); + unlock_inode(inode); done: return DO_STATUS(errno); @@ -704,34 +931,41 @@ __DEFINE_LXSYSCALL3(int, write, int, fd, void*, buf, size_t, count) 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 & VFS_IFDIR)) { + 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(); + __vfs_touch_inode(inode, INODE_MODIFY); + 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); @@ -746,35 +980,47 @@ __DEFINE_LXSYSCALL3(int, lseek, int, fd, int, offset, int, options) } 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); + if (!check_allow_read(inode)) { + errno = EPERM; + goto done; + } + + 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 = __builtin_sadd_overflow((int)file->f_pos, offset, &fpos); + overflow = sadd_of((int)file->f_pos, offset, &fpos); break; case FSEEK_END: - overflow = - __builtin_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); @@ -817,29 +1063,46 @@ vfs_readlink(struct v_dnode* dnode, char* buf, size_t size) { 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; + + if (!check_allow_read(inode)) { + return EPERM; + } + + 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) { - switch (itype) { - case VFS_IFDIR: - return DT_DIR; - case VFS_IFSYMLINK: - return DT_SYMLINK; - default: - return DT_PIPE; + 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) @@ -876,16 +1139,8 @@ __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 +1148,8 @@ __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))) { @@ -925,6 +1182,11 @@ __DEFINE_LXSYSCALL1(int, rmdir, const char*, pathname) lock_dnode(dnode); + if (!__check_unlinkable(dnode)) { + errno = EPERM; + goto done; + } + if ((errno = vfs_check_writable(dnode))) { goto done; } @@ -954,7 +1216,7 @@ __DEFINE_LXSYSCALL1(int, rmdir, const char*, pathname) lock_dnode(parent); lock_inode(parent->inode); - if ((dnode->inode->itype & VFS_IFDIR)) { + if (check_directory_node(dnode->inode)) { errno = parent->inode->ops->rmdir(parent->inode, dnode); if (!errno) { vfs_dcache_remove(dnode); @@ -982,6 +1244,11 @@ __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; } @@ -991,16 +1258,18 @@ __DEFINE_LXSYSCALL1(int, mkdir, const char*, path) 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 & VFS_IFDIR)) { + } 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; } @@ -1008,13 +1277,13 @@ __DEFINE_LXSYSCALL1(int, mkdir, const char*, path) vfs_d_free(dir); cleanup: - unlock_inode(parent->inode); + unlock_inode(inode); unlock_dnode(parent); done: return DO_STATUS(errno); } -int +static int __vfs_do_unlink(struct v_dnode* dnode) { int errno; @@ -1024,6 +1293,10 @@ __vfs_do_unlink(struct v_dnode* dnode) return EBUSY; } + if (!__check_unlinkable(dnode)) { + return EPERM; + } + if ((errno = vfs_check_writable(dnode))) { return errno; } @@ -1032,10 +1305,8 @@ __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 - errno = inode->ops->unlink(inode); + } else if (!check_directory_node(inode)) { + errno = inode->ops->unlink(inode, dnode); if (!errno) { vfs_d_free(dnode); } @@ -1082,18 +1353,30 @@ done: __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_EMPTY); - if (!errno) { - errno = EEXIST; - } else if (name_file) { - 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); } @@ -1117,7 +1400,7 @@ vfs_dup_fd(struct v_fd* old, struct v_fd** new) memcpy(copied, old, sizeof(struct v_fd)); - atomic_fetch_add(&old->file->ref_count, 1); + vfs_ref_file(old->file); *new = copied; @@ -1179,74 +1462,79 @@ 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 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; + } + + file = floc.file; + errno = __vfs_mknod(floc.dir->inode, file, VFS_IFSYMLINK, NULL); + if (errno) { + vfs_d_free(file); goto done; } - if (errno = vfs_check_writable(dnode)) { + f_ino = file->inode; + + assert(f_ino); + + errno = vfs_check_writable(file); + if (errno) { goto done; } - if (!dnode->inode->ops->set_symlink) { + if (!f_ino->ops->set_symlink) { errno = ENOTSUP; goto done; } - lock_inode(dnode->inode); + lock_inode(f_ino); - errno = dnode->inode->ops->set_symlink(dnode->inode, link_target); + errno = f_ino->ops->set_symlink(f_ino, link_target); - unlock_inode(dnode->inode); + unlock_inode(f_ino); done: + __floc_try_unlock(&floc); return DO_STATUS(errno); } -void -vfs_ref_dnode(struct v_dnode* dnode) +static int +vfs_do_chdir_nolock(struct proc_info* proc, struct v_dnode* dnode) { - atomic_fetch_add(&dnode->ref_count, 1); - mnt_mkbusy(dnode->mnt); -} + if (!check_directory_node(dnode->inode)) { + return ENOTDIR; + } -void -vfs_unref_dnode(struct v_dnode* dnode) -{ - atomic_fetch_sub(&dnode->ref_count, 1); - mnt_chillax(dnode->mnt); + if (proc->cwd) { + vfs_unref_dnode(proc->cwd); + } + + vfs_ref_dnode(dnode); + proc->cwd = dnode; + + return 0; } -int +static int vfs_do_chdir(struct proc_info* proc, struct v_dnode* dnode) { int errno = 0; lock_dnode(dnode); - if (!(dnode->inode->itype & VFS_IFDIR)) { - errno = ENOTDIR; - goto done; - } - - if (proc->cwd) { - vfs_unref_dnode(proc->cwd); - } - - vfs_ref_dnode(dnode); - proc->cwd = dnode; + errno = vfs_do_chdir_nolock(proc, dnode); unlock_dnode(dnode); -done: return errno; } @@ -1259,7 +1547,7 @@ __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 +1562,32 @@ __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); +} + + +__DEFINE_LXSYSCALL1(int, chroot, const char*, path) +{ + int errno; + struct v_dnode* dnode; + if ((errno = vfs_walk_proc(path, &dnode, NULL, 0))) { + return errno; + } + + lock_dnode(dnode); + + errno = vfs_do_chdir_nolock(__current, dnode); + if (errno) { + unlock_dnode(dnode); + goto done; + } + + __current->root = dnode; + + unlock_dnode(dnode); done: return DO_STATUS(errno); @@ -1302,12 +1615,12 @@ __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 +1633,7 @@ 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 +1717,158 @@ __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->st_ino = vino->id; + stat->st_blocks = vino->lb_usage; + stat->st_size = vino->fsize; + stat->st_blksize = vino->sb->blksize; + stat->st_nlink = vino->link_count; + stat->st_uid = vino->uid; + stat->st_gid = vino->gid; + + stat->st_ctim = vino->ctime; + stat->st_atim = vino->atime; + stat->st_mtim = vino->mtime; + + stat->st_mode = (vino->itype << 16) | vino->acl; + + stat->st_ioblksize = PAGE_SIZE; + + if (check_device_node(vino)) { + struct device* rdev = resolve_device(vino->data); + if (!rdev) { + errno = EINVAL; + goto done; + } + + stat->st_rdev = (dev_t){.meta = rdev->ident.fn_grp, + .unique = rdev->ident.unique, + .index = dev_uid(rdev) }; + } + + if (fdev) { + stat->st_dev = (dev_t){.meta = fdev->ident.fn_grp, + .unique = fdev->ident.unique, + .index = dev_uid(fdev) }; + } + +done: + return DO_STATUS(errno); +} + +__DEFINE_LXSYSCALL4(int, fchmodat, int, fd, + const char*, path, int, mode, int, flags) +{ + int errno; + struct v_dnode *dnode; + struct v_inode* inode; + + errno = vfs_walkat(fd, path, flags, &dnode); + if (errno) { + goto done; + } + + errno = vfs_check_writable(dnode); + if (errno) { + return errno; + } + + inode = dnode->inode; + lock_inode(inode); + + if (!current_is_root()) { + mode = mode & FSACL_RWXMASK; + } + + inode->acl = mode; + __vfs_touch_inode(inode, INODE_MODIFY); + + unlock_inode(inode); + +done: + return DO_STATUS(errno); +} + +__DEFINE_LXSYSCALL5(int, fchownat, int, fd, + const char*, path, uid_t, uid, gid_t, gid, int, flags) +{ + int errno; + struct v_dnode *dnode; + struct v_inode *inode; + + errno = vfs_walkat(fd, path, flags, &dnode); + if (errno) { + goto done; + } + + errno = vfs_check_writable(dnode); + if (errno) { + return errno; + } + + inode = dnode->inode; + lock_inode(inode); + + inode->uid = uid; + inode->gid = gid; + __vfs_touch_inode(inode, INODE_MODIFY); + + unlock_inode(inode); + +done: + return DO_STATUS(errno); +} + +__DEFINE_LXSYSCALL4(int, faccessat, int, fd, + const char*, path, int, amode, int, flags) +{ + int errno, acl; + struct v_dnode *dnode; + struct v_inode *inode; + struct user_scope* uscope; + + uid_t tuid; + gid_t tgid; + + errno = vfs_walkat(fd, path, flags, &dnode); + if (errno) { + goto done; + } + + if ((flags & AT_EACCESS)) { + tuid = current_euid(); + tgid = current_egid(); + } + else { + uscope = current_user_scope(); + tuid = uscope->ruid; + tgid = uscope->rgid; + } + + inode = dnode->inode; + + acl = inode->acl; + acl &= amode; + acl &= check_acl_between(inode->uid, inode->gid, tuid, tgid); + if (!acl) { + errno = EACCESS; + } + +done: return DO_STATUS(errno); } \ No newline at end of file