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- /* -*- mode:c; c-file-style:"k&r"; c-basic-offset: 4; tab-width:4; indent-tabs-mode:nil; mode:auto-fill; fill-column:78; -*- */
- /* vim: set ts=4 sw=4 et tw=78 fo=cqt wm=0: */
- /* Copyright (C) 2014 OSCAR lab, Stony Brook University
- This file is part of Graphene Library OS.
- Graphene Library OS is free software: you can redistribute it and/or
- modify it under the terms of the GNU General Public License
- as published by the Free Software Foundation, either version 3 of the
- License, or (at your option) any later version.
- Graphene Library OS is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- /*
- * shim_fs.c
- *
- * This file contains codes for creating filesystems in library OS.
- */
- #include <shim_internal.h>
- #include <shim_utils.h>
- #include <shim_fs.h>
- #include <shim_checkpoint.h>
- #include <pal.h>
- #include <pal_error.h>
- #include <pal_debug.h>
- #include <list.h>
- #include <linux/fcntl.h>
- struct shim_fs {
- char name[8];
- struct shim_fs_ops * fs_ops;
- struct shim_d_ops * d_ops;
- };
- #define NUM_MOUNTABLE_FS 3
- struct shim_fs mountable_fs [NUM_MOUNTABLE_FS] = {
- { .name = "chroot", .fs_ops = &chroot_fs_ops, .d_ops = &chroot_d_ops, },
- { .name = "proc", .fs_ops = &proc_fs_ops, .d_ops = &proc_d_ops, },
- { .name = "dev", .fs_ops = &dev_fs_ops, .d_ops = &dev_d_ops, },
- };
- #define NUM_BUILTIN_FS 4
- struct shim_mount * builtin_fs [NUM_BUILTIN_FS] = {
- &chroot_builtin_fs,
- &pipe_builtin_fs,
- &socket_builtin_fs,
- &epoll_builtin_fs,
- };
- static LOCKTYPE mount_mgr_lock;
- #define system_lock() lock(mount_mgr_lock)
- #define system_unlock() unlock(mount_mgr_lock)
- #define MOUNT_MGR_ALLOC 64
- #define PAGE_SIZE allocsize
- #define OBJ_TYPE struct shim_mount
- #include <memmgr.h>
- static MEM_MGR mount_mgr = NULL;
- DEFINE_LISTP(shim_mount);
- /* Links to mount->list */
- static LISTP_TYPE(shim_mount) mount_list;
- static LOCKTYPE mount_list_lock;
- int init_fs (void)
- {
- mount_mgr = create_mem_mgr(init_align_up(MOUNT_MGR_ALLOC));
- if (!mount_mgr)
- return -ENOMEM;
- create_lock(mount_mgr_lock);
- create_lock(mount_list_lock);
- return 0;
- }
- static struct shim_mount * alloc_mount (void)
- {
- return get_mem_obj_from_mgr_enlarge(mount_mgr,
- size_align_up(MOUNT_MGR_ALLOC));
- }
- static bool mount_migrated = false;
- static int __mount_root (void)
- {
- int ret;
- if ((ret = mount_fs("chroot", "file:", "/")) < 0) {
- debug("mounting root filesystem failed (%e)\n", ret);
- return ret;
- }
- return 0;
- }
- static int __mount_sys (void)
- {
- int ret;
- debug("mounting as proc filesystem: /proc\n");
- if ((ret = mount_fs("proc", NULL, "/proc")) < 0) {
- debug("mounting proc filesystem failed (%e)\n", ret);
- return ret;
- }
- debug("mounting as dev filesystem: /dev\n");
- if ((ret = mount_fs("dev", NULL, "/dev")) < 0) {
- debug("mounting dev filesystem failed (%e)\n", ret);
- return ret;
- }
- debug("mounting as chroot filesystem: from dev:tty to /dev\n");
- if ((ret = mount_fs("chroot", "dev:tty", "/dev/tty")) < 0) {
- debug("mounting terminal device failed (%e)\n", ret);
- return ret;
- }
- return 0;
- }
- static int __mount_one_other (const char * key, int keylen)
- {
- if (!root_config)
- return 0;
- char k[CONFIG_MAX], p[CONFIG_MAX], u[CONFIG_MAX],
- t[CONFIG_MAX];
- char * uri = NULL;
- int ret;
- memcpy(k, "fs.mount.", 9);
- memcpy(k + 9, key, keylen);
- char * kp = k + 9 + keylen;
- memcpy(kp, ".path", 6);
- if (get_config(root_config, k, p, CONFIG_MAX) <= 0)
- return -EINVAL;
- memcpy(kp, ".type", 6);
- if (get_config(root_config, k, t, CONFIG_MAX) <= 0)
- return -EINVAL;
- memcpy(kp, ".uri", 5);
- if (get_config(root_config, k, u, CONFIG_MAX) > 0)
- uri = u;
- debug("mounting as %s filesystem: from %s to %s\n", t, uri, p);
- if ((ret = mount_fs(t, uri, p)) < 0) {
- debug("mounting %s on %s (type=%s) failed (%e)\n", uri, p, t,
- -ret);
- return ret;
- }
- return 0;
- }
- static int __mount_others (void)
- {
- if (!root_config)
- return 0;
- int nkeys, keybuf_size = CONFIG_MAX;
- char * keybuf = __alloca(keybuf_size);
- while ((nkeys = get_config_entries(root_config, "fs.mount", keybuf,
- keybuf_size)) == -ENAMETOOLONG) {
- keybuf = __alloca(keybuf_size);
- keybuf_size *= 2;
- }
- if (nkeys < 0)
- return 0;
- const char * key = keybuf, * next = NULL;
- for (int n = 0 ; n < nkeys ; key = next, n++) {
- for (next = key ; *next ; next++);
- next++;
- int ret = __mount_one_other(key, next - key - 1);
- if (ret < 0)
- return ret;
- }
- return 0;
- }
- int init_mount_root (void)
- {
- if (mount_migrated)
- return 0;
- int ret;
- if ((ret = __mount_root()) < 0)
- return ret;
- if ((ret = __mount_sys()) < 0)
- return ret;
- return 0;
- }
- int init_mount (void)
- {
- if (mount_migrated)
- return 0;
- int ret;
- if ((ret = __mount_others()) < 0)
- return ret;
- return 0;
- }
- static inline struct shim_fs * find_fs (const char * type)
- {
- struct shim_fs * fs = NULL;
- int len = strlen(type);
- for (int i = 0 ; i < NUM_MOUNTABLE_FS ; i++)
- if (!memcmp(type, mountable_fs[i].name, len + 1)) {
- fs = &mountable_fs[i];
- break;
- }
- return fs;
- }
- int search_builtin_fs (const char * type, struct shim_mount ** fs)
- {
- int len = strlen(type);
- for (int i = 0 ; i < NUM_BUILTIN_FS ; i++)
- if (!memcmp(type, builtin_fs[i]->type, len + 1)) {
- *fs = builtin_fs[i];
- return 0;
- }
- return -ENOENT;
- }
- int __mount_fs (struct shim_mount * mount, struct shim_dentry * dent)
- {
- int ret = 0;
- dent->state |= DENTRY_MOUNTPOINT;
- get_dentry(dent);
- mount->mount_point = dent;
- dent->mounted = mount;
- struct shim_dentry * mount_root = mount->root;
- if (!mount_root) {
- mount_root = get_new_dentry(NULL, "", 0);
- mount_root->fs = mount;
- /* mount_root->state |= DENTRY_VALID; */
- qstrsetstr(&mount_root->name, dentry_get_name(dent),
- dent->name.len);
- if (mount->d_ops && mount->d_ops->lookup &&
- (ret = mount->d_ops->lookup(mount_root, 0)) < 0 &&
- ret != -ESKIPPED)
- return ret;
- mount->root = mount_root;
- }
- mount_root->state |= dent->state & (DENTRY_REACHABLE|DENTRY_UNREACHABLE);
- __add_dcache(mount_root, &mount->path.hash);
- if ((ret = __del_dentry_tree(dent)) < 0)
- return ret;
- lock(mount_list_lock);
- get_mount(mount);
- listp_add_tail(mount, &mount_list, list);
- unlock(mount_list_lock);
- do {
- struct shim_dentry * parent = dent->parent;
- if (dent->state & DENTRY_ANCESTER) {
- put_dentry(dent);
- break;
- }
- dent->state |= DENTRY_ANCESTER;
- if (parent)
- get_dentry(parent);
- put_dentry(dent);
- dent = parent;
- } while (dent);
- return 0;
- }
- int mount_fs (const char * type, const char * uri, const char * mount_point)
- {
- int ret = 0;
- struct shim_fs * fs = find_fs(type);
- if (!fs || !fs->fs_ops || !fs->fs_ops->mount) {
- ret = -ENODEV;
- goto out;
- }
- lock(dcache_lock);
- struct shim_dentry * dent;
- if ((ret = __path_lookupat(NULL, mount_point, 0, &dent)) < 0)
- goto out;
- struct shim_mount * mount = alloc_mount();
- void * mount_data = NULL;
- /* call fs-specific mount to allocate mount_data */
- if ((ret = fs->fs_ops->mount(uri, mount_point, &mount_data)) < 0)
- goto out;
- int uri_len = uri ? strlen(uri) : 0;
- qstrsetstr(&mount->path, mount_point, strlen(mount_point));
- qstrsetstr(&mount->uri, uri, uri_len);
- memcpy(mount->type, fs->name, sizeof(fs->name));
- mount->fs_ops = fs->fs_ops;
- mount->d_ops = fs->d_ops;
- mount->data = mount_data;
- mount->path.hash = dent->rel_path.hash;
- ret = __mount_fs(mount, dent);
- out:
- unlock(dcache_lock);
- return ret;
- }
- void get_mount (struct shim_mount * mount)
- {
- REF_INC(mount->ref_count);
- }
- void put_mount (struct shim_mount * mount)
- {
- REF_DEC(mount->ref_count);
- }
- int walk_mounts (int (*walk) (struct shim_mount * mount, void * arg),
- void * arg)
- {
- struct shim_mount * mount, * n;
- int ret;
- int nsrched = 0;
- lock(mount_list_lock);
- listp_for_each_entry_safe(mount, n, &mount_list, list) {
- if ((ret = (*walk) (mount, arg)) < 0)
- break;
- if (ret > 0)
- nsrched++;
- }
- unlock(mount_list_lock);
- return ret < 0 ? ret : (nsrched ? 0 : -ESRCH);
- }
- struct shim_mount * find_mount_from_uri (const char * uri)
- {
- struct shim_mount * mount, * found = NULL;
- int longest_path = 0;
- lock(mount_list_lock);
- listp_for_each_entry(mount, &mount_list, list) {
- if (qstrempty(&mount->uri))
- continue;
- if (!memcmp(qstrgetstr(&mount->uri), uri, mount->uri.len) &&
- (uri[mount->uri.len] == '/' || uri[mount->uri.len] == '/')) {
- if (mount->path.len > longest_path) {
- longest_path = mount->path.len;
- found = mount;
- }
- }
- }
- if (found)
- get_mount(found);
- unlock(mount_list_lock);
- return found;
- }
- BEGIN_CP_FUNC(mount)
- {
- assert(size == sizeof(struct shim_mount));
- struct shim_mount * mount = (struct shim_mount *) obj;
- struct shim_mount * new_mount = NULL;
- ptr_t off = GET_FROM_CP_MAP(obj);
- if (!off) {
- off = ADD_CP_OFFSET(sizeof(struct shim_mount));
- ADD_TO_CP_MAP(obj, off);
- if (!mount->cpdata &&
- mount->fs_ops &&
- mount->fs_ops->checkpoint) {
- void * cpdata = NULL;
- int bytes = mount->fs_ops->checkpoint(&cpdata, mount->data);
- if (bytes > 0) {
- mount->cpdata = cpdata;
- mount->cpsize = bytes;
- }
- }
- new_mount = (struct shim_mount *) (base + off);
- *new_mount = *mount;
- if (mount->cpdata) {
- struct shim_mem_entry * entry;
- DO_CP_SIZE(memory, mount->cpdata, mount->cpsize, &entry);
- new_mount->cpdata = NULL;
- entry->paddr = &new_mount->cpdata;
- }
- new_mount->data = NULL;
- new_mount->mount_point = NULL;
- new_mount->root = NULL;
- INIT_LIST_HEAD(new_mount, list);
- DO_CP_IN_MEMBER(qstr, new_mount, path);
- DO_CP_IN_MEMBER(qstr, new_mount, uri);
- if (mount->mount_point)
- DO_CP_MEMBER(dentry, mount, new_mount, mount_point);
- if (mount->root)
- DO_CP_MEMBER(dentry, mount, new_mount, root);
- ADD_CP_FUNC_ENTRY(off);
- } else {
- new_mount = (struct shim_mount *) (base + off);
- }
- if (objp)
- *objp = (void *) new_mount;
- }
- END_CP_FUNC(mount)
- BEGIN_RS_FUNC(mount)
- {
- struct shim_mount * mount = (void *) (base + GET_CP_FUNC_ENTRY());
- CP_REBASE(mount->cpdata);
- CP_REBASE(mount->list);
- CP_REBASE(mount->mount_point);
- CP_REBASE(mount->root);
- struct shim_fs * fs = find_fs(mount->type);
- if (fs && fs->fs_ops && fs->fs_ops->migrate && mount->cpdata) {
- void * mount_data = NULL;
- if (fs->fs_ops->migrate(mount->cpdata, &mount_data) == 0)
- mount->data = mount_data;
- mount->cpdata = NULL;
- }
- mount->fs_ops = fs->fs_ops;
- mount->d_ops = fs->d_ops;
- listp_add_tail(mount, &mount_list, list);
- if (!qstrempty(&mount->path)) {
- DEBUG_RS("type=%s,uri=%s,path=%s", mount->type, qstrgetstr(&mount->uri),
- qstrgetstr(&mount->path));
- } else {
- DEBUG_RS("type=%s,uri=%s", mount->type, qstrgetstr(&mount->uri));
- }
- }
- END_RS_FUNC(mount)
- BEGIN_CP_FUNC(all_mounts)
- {
- struct shim_mount * mount;
- lock(mount_list_lock);
- listp_for_each_entry(mount, &mount_list, list)
- DO_CP(mount, mount, NULL);
- unlock(mount_list_lock);
- /* add an empty entry to mark as migrated */
- ADD_CP_FUNC_ENTRY(0);
- }
- END_CP_FUNC(all_mounts)
- BEGIN_RS_FUNC(all_mounts)
- {
- /* to prevent file system from being mount again */
- mount_migrated = true;
- }
- END_RS_FUNC(all_mounts)
- const char * get_file_name (const char * path, size_t len)
- {
- const char * c = path + len - 1;
- while (c > path && *c != '/')
- c--;
- return *c == '/' ? c + 1 : c;
- }
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