X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/bc4c6e1218d6903b07c32b11ea7d3c82c463686e..c4510182f3c02e390184bee518940e325f064b20:/lunaix-os/kernel/fs/vfs.c

diff --git a/lunaix-os/kernel/fs/vfs.c b/lunaix-os/kernel/fs/vfs.c
index c13b8d3..0c2f42d 100644
--- a/lunaix-os/kernel/fs/vfs.c
+++ b/lunaix-os/kernel/fs/vfs.c
@@ -56,22 +56,6 @@
 
 #include <lunaix/fs/twifs.h>
 
-#define PATH_DELIM '/'
-
-#define unlock_inode(inode) mutex_unlock(&inode->lock)
-#define lock_inode(inode)                                                      \
-    ({                                                                         \
-        mutex_lock(&inode->lock);                                              \
-        lru_use_one(inode_lru, &inode->lru);                                   \
-    })
-
-#define unlock_dnode(dnode) mutex_unlock(&dnode->lock)
-#define lock_dnode(dnode)                                                      \
-    ({                                                                         \
-        mutex_lock(&dnode->lock);                                              \
-        lru_use_one(dnode_lru, &dnode->lru);                                   \
-    })
-
 static struct cake_pile* dnode_pile;
 static struct cake_pile* inode_pile;
 static struct cake_pile* file_pile;
@@ -81,7 +65,7 @@ static struct cake_pile* fd_pile;
 struct v_dnode* vfs_sysroot;
 static struct hbucket* dnode_cache;
 
-static struct lru_zone *dnode_lru, *inode_lru;
+struct lru_zone *dnode_lru, *inode_lru;
 
 struct hstr vfs_ddot = HSTR("..", 2);
 struct hstr vfs_dot = HSTR(".", 1);
@@ -120,6 +104,7 @@ 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);
 }
 
@@ -142,7 +127,7 @@ vfs_dcache_lookup(struct v_dnode* parent, struct hstr* str)
         return parent;
 
     if (HSTR_EQ(str, &vfs_ddot)) {
-        return parent->parent ? parent->parent : parent;
+        return parent->parent;
     }
 
     uint32_t hash = str->hash;
@@ -194,176 +179,6 @@ vfs_dcache_rehash(struct v_dnode* new_parent, struct v_dnode* dnode)
     vfs_dcache_add(new_parent, dnode);
 }
 
-#define VFS_SYMLINK_DEPTH 16
-
-int
-__vfs_walk(struct v_dnode* start,
-           const char* path,
-           struct v_dnode** dentry,
-           struct hstr* component,
-           int walk_options,
-           size_t depth,
-           char* fname_buffer)
-{
-    int errno = 0;
-    int i = 0, j = 0;
-
-    if (depth >= VFS_SYMLINK_DEPTH) {
-        return ENAMETOOLONG;
-    }
-
-    if (path[0] == PATH_DELIM || !start) {
-        if ((walk_options & VFS_WALK_FSRELATIVE) && start) {
-            start = start->super_block->root;
-        } else {
-            start = vfs_sysroot;
-            if (!vfs_sysroot->mnt) {
-                panick("vfs: no root");
-            }
-        }
-        i++;
-    }
-
-    struct v_dnode* dnode;
-    struct v_inode* current_inode;
-    struct v_dnode* current_level = start;
-
-    struct hstr name = HSTR(fname_buffer, 0);
-
-    char current = path[i++], lookahead;
-    while (current && current_level) {
-        lookahead = path[i++];
-        if (current != PATH_DELIM) {
-            if (j >= VFS_NAME_MAXLEN - 1) {
-                return ENAMETOOLONG;
-            }
-            if (!VFS_VALID_CHAR(current)) {
-                return EINVAL;
-            }
-            fname_buffer[j++] = current;
-            if (lookahead) {
-                goto cont;
-            }
-        }
-
-        // handling cases like /^.*(\/+).*$/
-        if (lookahead == PATH_DELIM) {
-            goto cont;
-        }
-
-        fname_buffer[j] = 0;
-        name.len = j;
-        hstr_rehash(&name, HSTR_FULL_HASH);
-
-        if (!lookahead && (walk_options & VFS_WALK_PARENT)) {
-            if (component) {
-                component->hash = name.hash;
-                component->len = j;
-                strcpy(component->value, fname_buffer);
-            }
-            break;
-        }
-
-        current_inode = current_level->inode;
-
-        if ((current_inode->itype & VFS_IFSYMLINK)) {
-            const char* link;
-
-            lock_inode(current_inode);
-            if ((errno =
-                   current_inode->ops->read_symlink(current_inode, &link))) {
-                unlock_inode(current_inode);
-                goto error;
-            }
-            unlock_inode(current_inode);
-
-            errno = __vfs_walk(current_level->parent,
-                               link,
-                               &dnode,
-                               NULL,
-                               0,
-                               depth + 1,
-                               fname_buffer + name.len + 1);
-
-            if (errno) {
-                goto error;
-            }
-
-            // reposition the resolved subtree pointed by symlink
-            vfs_dcache_rehash(current_level->parent, dnode);
-            current_level = dnode;
-            current_inode = dnode->inode;
-        }
-
-        lock_dnode(current_level);
-
-        dnode = vfs_dcache_lookup(current_level, &name);
-
-        if (!dnode) {
-            dnode = vfs_d_alloc(current_level, &name);
-
-            if (!dnode) {
-                errno = ENOMEM;
-                goto error;
-            }
-
-            lock_inode(current_inode);
-
-            errno = current_inode->ops->dir_lookup(current_inode, dnode);
-
-            if (errno == ENOENT && (walk_options & VFS_WALK_MKPARENT)) {
-                if (!current_inode->ops->mkdir) {
-                    errno = ENOTSUP;
-                } else {
-                    errno = current_inode->ops->mkdir(current_inode, dnode);
-                }
-            }
-
-            vfs_dcache_add(current_level, dnode);
-            unlock_inode(current_inode);
-
-            if (errno) {
-                unlock_dnode(current_level);
-                goto cleanup;
-            }
-        }
-
-        unlock_dnode(current_level);
-
-        j = 0;
-        current_level = dnode;
-    cont:
-        current = lookahead;
-    };
-
-    *dentry = current_level;
-    return 0;
-
-cleanup:
-    vfs_d_free(dnode);
-error:
-    *dentry = NULL;
-    return errno;
-}
-
-int
-vfs_walk(struct v_dnode* start,
-         const char* path,
-         struct v_dnode** dentry,
-         struct hstr* component,
-         int options)
-{
-    // allocate a file name stack for path walking and recursion to resolve
-    // symlink
-    char* name_buffer = valloc(2048);
-
-    int errno =
-      __vfs_walk(start, path, dentry, component, options, 0, name_buffer);
-
-    vfree(name_buffer);
-    return errno;
-}
-
 int
 vfs_open(struct v_dnode* dnode, struct v_file** file)
 {
@@ -421,6 +236,10 @@ vfs_link(struct v_dnode* to_link, struct v_dnode* name)
 {
     int errno;
 
+    if ((errno = vfs_check_writable(to_link))) {
+        return errno;
+    }
+
     lock_inode(to_link->inode);
     if (to_link->super_block->root != name->super_block->root) {
         errno = EXDEV;
@@ -452,11 +271,16 @@ vfs_close(struct v_file* file)
 int
 vfs_fsync(struct v_file* file)
 {
+    int errno;
+    if ((errno = vfs_check_writable(file->dnode))) {
+        return errno;
+    }
+
     lock_inode(file->inode);
 
-    int errno = ENOTSUP;
     pcache_commit_all(file->inode);
 
+    errno = ENOTSUP;
     if (file->ops->sync) {
         errno = file->ops->sync(file);
     }
@@ -543,6 +367,7 @@ vfs_d_alloc(struct v_dnode* parent, struct hstr* name)
 
     if (parent) {
         dnode->super_block = parent->super_block;
+        dnode->mnt = parent->mnt;
     }
 
     lru_use_one(dnode_lru, &dnode->lru);
@@ -614,6 +439,7 @@ vfs_i_alloc(struct v_superblock* sb)
 
     memset(inode, 0, sizeof(*inode));
     mutex_init(&inode->lock);
+    llist_init_head(&inode->xattrs);
 
     sb->ops.init_inode(sb, inode);
 
@@ -644,7 +470,7 @@ vfs_i_free(struct v_inode* inode)
 #define FLOCATE_CREATE_EMPTY 1
 
 int
-__vfs_getfd(int fd, struct v_fd** fd_s)
+vfs_getfd(int fd, struct v_fd** fd_s)
 {
     if (TEST_FD(fd) && (*fd_s = __current->fdtable->fds[fd])) {
         return 0;
@@ -661,8 +487,9 @@ __vfs_try_locate_file(const char* path,
     char name_str[VFS_NAME_MAXLEN];
     struct hstr name = HSTR(name_str, 0);
     int errno;
-    if ((errno =
-           vfs_walk(__current->cwd, path, fdir, &name, VFS_WALK_PARENT))) {
+
+    name_str[0] = 0;
+    if ((errno = vfs_walk_proc(path, fdir, &name, VFS_WALK_PARENT))) {
         return errno;
     }
 
@@ -730,7 +557,7 @@ __DEFINE_LXSYSCALL1(int, close, int, fd)
 {
     struct v_fd* fd_s;
     int errno = 0;
-    if ((errno = __vfs_getfd(fd, &fd_s))) {
+    if ((errno = vfs_getfd(fd, &fd_s))) {
         goto done_err;
     }
 
@@ -764,7 +591,7 @@ __DEFINE_LXSYSCALL2(int, readdir, int, fd, struct dirent*, dent)
     struct v_fd* fd_s;
     int errno;
 
-    if ((errno = __vfs_getfd(fd, &fd_s))) {
+    if ((errno = vfs_getfd(fd, &fd_s))) {
         goto done;
     }
 
@@ -805,7 +632,7 @@ __DEFINE_LXSYSCALL3(int, read, int, fd, void*, buf, size_t, count)
 {
     int errno = 0;
     struct v_fd* fd_s;
-    if ((errno = __vfs_getfd(fd, &fd_s))) {
+    if ((errno = vfs_getfd(fd, &fd_s))) {
         goto done;
     }
 
@@ -843,11 +670,16 @@ __DEFINE_LXSYSCALL3(int, write, int, fd, void*, buf, size_t, count)
 {
     int errno = 0;
     struct v_fd* fd_s;
-    if ((errno = __vfs_getfd(fd, &fd_s))) {
+    if ((errno = vfs_getfd(fd, &fd_s))) {
         goto done;
     }
 
     struct v_file* file = fd_s->file;
+
+    if ((errno = vfs_check_writable(file->dnode))) {
+        goto done;
+    }
+
     if ((file->inode->itype & VFS_IFDIR)) {
         errno = EISDIR;
         goto done;
@@ -881,27 +713,36 @@ __DEFINE_LXSYSCALL3(int, lseek, int, fd, int, offset, int, options)
 {
     int errno = 0;
     struct v_fd* fd_s;
-    if ((errno = __vfs_getfd(fd, &fd_s))) {
+    if ((errno = vfs_getfd(fd, &fd_s))) {
         goto done;
     }
 
     struct v_file* file = fd_s->file;
 
+    if (!file->ops->seek) {
+        errno = ENOTSUP;
+        goto done;
+    }
+
     lock_inode(file->inode);
 
-    size_t fpos = file->f_pos;
+    int overflow = 0;
+    int fpos = file->f_pos;
     switch (options) {
         case FSEEK_CUR:
-            fpos = (size_t)((int)file->f_pos + offset);
+            overflow = __builtin_sadd_overflow((int)file->f_pos, offset, &fpos);
             break;
         case FSEEK_END:
-            fpos = (size_t)((int)file->inode->fsize + offset);
+            overflow =
+              __builtin_sadd_overflow((int)file->inode->fsize, offset, &fpos);
             break;
         case FSEEK_SET:
             fpos = offset;
             break;
     }
-    if (!(errno = file->ops->seek(file->inode, fpos))) {
+    if (overflow) {
+        errno = EOVERFLOW;
+    } else if (!(errno = file->ops->seek(file->inode, fpos))) {
         file->f_pos = fpos;
     }
 
@@ -914,12 +755,12 @@ done:
 int
 vfs_get_path(struct v_dnode* dnode, char* buf, size_t size, int depth)
 {
-    if (!dnode) {
+    if (!dnode || dnode->parent == dnode) {
         return 0;
     }
 
     if (depth > 64) {
-        return ELOOP;
+        return ENAMETOOLONG;
     }
 
     size_t len = vfs_get_path(dnode->parent, buf, size, depth + 1);
@@ -928,14 +769,12 @@ vfs_get_path(struct v_dnode* dnode, char* buf, size_t size, int depth)
         return len;
     }
 
+    buf[len++] = VFS_PATH_DELIM;
+
     size_t cpy_size = MIN(dnode->name.len, size - len);
     strncpy(buf + len, dnode->name.value, cpy_size);
     len += cpy_size;
 
-    if (len < size) {
-        buf[len++] = PATH_DELIM;
-    }
-
     return len;
 }
 
@@ -960,7 +799,7 @@ __DEFINE_LXSYSCALL3(int, realpathat, int, fd, char*, buf, size_t, size)
 {
     int errno;
     struct v_fd* fd_s;
-    if ((errno = __vfs_getfd(fd, &fd_s))) {
+    if ((errno = vfs_getfd(fd, &fd_s))) {
         goto done;
     }
 
@@ -979,8 +818,7 @@ __DEFINE_LXSYSCALL3(int, readlink, const char*, path, char*, buf, size_t, size)
 {
     int errno;
     struct v_dnode* dnode;
-    if (!(errno =
-            vfs_walk(__current->cwd, path, &dnode, NULL, VFS_WALK_NOFOLLOW))) {
+    if (!(errno = vfs_walk_proc(path, &dnode, NULL, VFS_WALK_NOFOLLOW))) {
         errno = vfs_readlink(dnode, buf, size);
     }
 
@@ -1004,7 +842,7 @@ __DEFINE_LXSYSCALL4(int,
 {
     int errno;
     struct v_fd* fd_s;
-    if ((errno = __vfs_getfd(dirfd, &fd_s))) {
+    if ((errno = vfs_getfd(dirfd, &fd_s))) {
         goto done;
     }
 
@@ -1034,12 +872,16 @@ __DEFINE_LXSYSCALL1(int, rmdir, const char*, pathname)
 {
     int errno;
     struct v_dnode* dnode;
-    if ((errno = vfs_walk(__current->cwd, pathname, &dnode, NULL, 0))) {
+    if ((errno = vfs_walk_proc(pathname, &dnode, NULL, 0))) {
         return DO_STATUS(errno);
     }
 
     lock_dnode(dnode);
 
+    if ((errno = vfs_check_writable(dnode))) {
+        goto done;
+    }
+
     if ((dnode->super_block->fs->types & FSTYPE_ROFS)) {
         errno = EROFS;
         goto done;
@@ -1089,17 +931,18 @@ __DEFINE_LXSYSCALL1(int, mkdir, const char*, path)
     char name_value[VFS_NAME_MAXLEN];
     struct hstr name = HHSTR(name_value, 0, 0);
 
-    if (!dir) {
-        errno = ENOMEM;
+    if ((errno = vfs_walk_proc(path, &parent, &name, VFS_WALK_PARENT))) {
         goto done;
     }
 
-    if ((errno =
-           vfs_walk(__current->cwd, path, &parent, &name, VFS_WALK_PARENT))) {
+    if ((errno = vfs_check_writable(parent))) {
         goto done;
     }
 
-    dir = vfs_d_alloc(parent, &name);
+    if (!(dir = vfs_d_alloc(parent, &name))) {
+        errno = ENOMEM;
+        goto done;
+    }
 
     lock_dnode(parent);
     lock_inode(parent->inode);
@@ -1127,15 +970,19 @@ done:
 int
 __vfs_do_unlink(struct v_dnode* dnode)
 {
+    int errno;
     struct v_inode* inode = dnode->inode;
 
     if (dnode->ref_count > 1) {
         return EBUSY;
     }
 
+    if ((errno = vfs_check_writable(dnode))) {
+        return errno;
+    }
+
     lock_inode(inode);
 
-    int errno;
     if (inode->open_count) {
         errno = EBUSY;
     } else if (!(inode->itype & VFS_IFDIR)) {
@@ -1158,11 +1005,7 @@ __DEFINE_LXSYSCALL1(int, unlink, const char*, pathname)
 {
     int errno;
     struct v_dnode* dnode;
-    if ((errno = vfs_walk(__current->cwd, pathname, &dnode, NULL, 0))) {
-        goto done;
-    }
-    if ((dnode->super_block->fs->types & FSTYPE_ROFS)) {
-        errno = EROFS;
+    if ((errno = vfs_walk_proc(pathname, &dnode, NULL, 0))) {
         goto done;
     }
 
@@ -1176,7 +1019,7 @@ __DEFINE_LXSYSCALL2(int, unlinkat, int, fd, const char*, pathname)
 {
     int errno;
     struct v_fd* fd_s;
-    if ((errno = __vfs_getfd(fd, &fd_s))) {
+    if ((errno = vfs_getfd(fd, &fd_s))) {
         goto done;
     }
 
@@ -1211,7 +1054,8 @@ __DEFINE_LXSYSCALL1(int, fsync, int, fildes)
 {
     int errno;
     struct v_fd* fd_s;
-    if (!(errno = __vfs_getfd(fildes, &fd_s))) {
+
+    if (!(errno = vfs_getfd(fildes, &fd_s))) {
         errno = vfs_fsync(fd_s->file);
     }
 
@@ -1242,7 +1086,7 @@ vfs_dup2(int oldfd, int newfd)
 
     int errno;
     struct v_fd *oldfd_s, *newfd_s;
-    if ((errno = __vfs_getfd(oldfd, &oldfd_s))) {
+    if ((errno = vfs_getfd(oldfd, &oldfd_s))) {
         goto done;
     }
 
@@ -1274,7 +1118,7 @@ __DEFINE_LXSYSCALL1(int, dup, int, oldfd)
 {
     int errno, newfd;
     struct v_fd *oldfd_s, *newfd_s;
-    if ((errno = __vfs_getfd(oldfd, &oldfd_s))) {
+    if ((errno = vfs_getfd(oldfd, &oldfd_s))) {
         goto done;
     }
 
@@ -1297,13 +1141,14 @@ __DEFINE_LXSYSCALL2(int,
 {
     int errno;
     struct v_dnode* dnode;
-    if ((errno = vfs_walk(__current->cwd, pathname, &dnode, NULL, 0))) {
+    if ((errno = vfs_walk_proc(pathname, &dnode, NULL, 0))) {
         goto done;
     }
-    if ((dnode->super_block->fs->types & FSTYPE_ROFS)) {
-        errno = EROFS;
+
+    if (errno = vfs_check_writable(dnode)) {
         goto done;
     }
+
     if (!dnode->inode->ops->set_symlink) {
         errno = ENOTSUP;
         goto done;
@@ -1351,7 +1196,7 @@ __DEFINE_LXSYSCALL1(int, chdir, const char*, path)
     struct v_dnode* dnode;
     int errno = 0;
 
-    if ((errno = vfs_walk(__current->cwd, path, &dnode, NULL, 0))) {
+    if ((errno = vfs_walk_proc(path, &dnode, NULL, 0))) {
         goto done;
     }
 
@@ -1366,7 +1211,7 @@ __DEFINE_LXSYSCALL1(int, fchdir, int, fd)
     struct v_fd* fd_s;
     int errno = 0;
 
-    if ((errno = __vfs_getfd(fd, &fd_s))) {
+    if ((errno = vfs_getfd(fd, &fd_s))) {
         goto done;
     }
 
@@ -1388,7 +1233,7 @@ __DEFINE_LXSYSCALL2(char*, getcwd, char*, buf, size_t, size)
     size_t len = 0;
 
     if (!__current->cwd) {
-        *buf = PATH_DELIM;
+        *buf = VFS_PATH_DELIM;
         len = 1;
     } else {
         len = vfs_get_path(__current->cwd, buf, size, 0);
@@ -1410,11 +1255,16 @@ done:
 int
 vfs_do_rename(struct v_dnode* current, struct v_dnode* target)
 {
+    int errno = 0;
     if (current->inode->id == target->inode->id) {
         // hard link
         return 0;
     }
 
+    if (errno = vfs_check_writable(current)) {
+        return errno;
+    }
+
     if (current->ref_count > 1 || target->ref_count > 1) {
         return EBUSY;
     }
@@ -1423,8 +1273,6 @@ vfs_do_rename(struct v_dnode* current, struct v_dnode* target)
         return EXDEV;
     }
 
-    int errno = 0;
-
     struct v_dnode* oldparent = current->parent;
     struct v_dnode* newparent = target->parent;
 
@@ -1472,7 +1320,7 @@ __DEFINE_LXSYSCALL2(int, rename, const char*, oldpath, const char*, newpath)
     struct hstr name = HSTR(valloc(VFS_NAME_MAXLEN), 0);
     int errno = 0;
 
-    if ((errno = vfs_walk(__current->cwd, oldpath, &cur, NULL, 0))) {
+    if ((errno = vfs_walk_proc(oldpath, &cur, NULL, 0))) {
         goto done;
     }