int sys_stat(char *f, struct stat *statbuf, bool lin)
{
if(!f || !statbuf) return -EINVAL;
struct inode *i;
int res;
i = (struct inode *) (lin ? fs_path_resolve_inode(f, RESOLVE_NOLINK, &res) : fs_path_resolve_inode(f, 0, &res));
if(!i)
return res;
do_stat(i, statbuf);
vfs_icache_put(i);
return 0;
}
int fs_filesystem_init_mount(struct filesystem *fs, char *point, char *node, char *type, int opts)
{
if(type)
strncpy(fs->type, type, 128);
fs->opts = opts;
fs->pointname = kmalloc(strlen(point) + 1);
strncpy(fs->pointname, point, strlen(point));
if(!strcmp(fs->type, "devfs") || !strcmp(fs->type, "tmpfs")) {
fs->nodename = kmalloc(strlen(fs->type) + 1);
strncpy(fs->nodename, fs->type, strlen(fs->type));
if(fs->type[0] == 'd')
return 0;
} else {
fs->nodename = kmalloc(strlen(node) + 1);
strncpy(fs->nodename, node, strlen(node));
}
int err;
struct inode *i = fs_path_resolve_inode(node, 0, &err);
if(!i)
return err;
fs->dev = i->phys_dev;
fs->node = i;
if(!strcmp(fs->type, "tmpfs"))
return ramfs_mount(fs);
struct fsdriver *fd = 0;
if(type) {
if((fd = hash_lookup(&fsdrivershash, type, strlen(type))) == NULL)
return -EINVAL;
fs->driver = fd;
return fd->mount(fs);
} else {
if(linkedlist_find(&fsdriverslist, __fs_init_mount_find_driver, fs))
return 0;
}
return -EINVAL;
}
/* This is possibly the lengthiest function in the VFS (possibly in the entire kernel!).
* It resolves a path until the last name in the path string, and then tries to create
* a new file with that name. It requires a lot of in-sequence checks for permission,
* existance, is-a-directory, and so forth. */
struct inode *fs_path_resolve_create_get(const char *path, int flags, mode_t mode, int *result, struct dirent **dirent)
{
// Step 1: Split the path up into directory to create in, and name of new file.
int len = strlen(path) + 1;
char tmp[len];
memcpy(tmp, path, len);
char *del = strrchr(tmp, '/');
if(del)
*del = 0;
char *dirpath = del ? tmp : ".";
char *name = del ? del + 1 : tmp;
if(dirpath[0] == 0)
dirpath = "/";
if(dirent)
*dirent = 0;
if(result)
*result = 0;
// Step 2: Resolve the target directory.
struct inode *dir = fs_path_resolve_inode(dirpath, flags, result);
if(!dir)
return 0;
if(!S_ISDIR(dir->mode)) {
if(result) *result = -ENOTDIR;
return 0;
}
// Step 3: Try to look up the file that we're trying to create.
struct dirent *test = fs_dirent_lookup(dir, name, strlen(name));
if(test) {
// If it was found, return it and its inode.
if(dirent)
*dirent = test;
struct inode *ret = fs_dirent_readinode(test, true);
if(ret)
ret = fs_resolve_mount(ret);
if(!ret) {
if(dirent)
*dirent = 0;
if(result)
*result = -EIO;
vfs_dirent_release(test);
} else {
if(!dirent)
vfs_dirent_release(test);
if(result)
*result = 0;
}
vfs_icache_put(dir);
return ret;
}
// Didn't find the entry. Step 4: Create one.
if(!vfs_inode_check_permissions(dir, MAY_WRITE, 0)) {
if(result) *result = -EACCES;
vfs_icache_put(dir);
return 0;
}
if(dir->nlink == 1) {
if(result) *result = -ENOSPC;
vfs_icache_put(dir);
return 0;
}
uint32_t id;
// Step 4a: Allocate an inode.
int r = fs_callback_fs_alloc_inode(dir->filesystem, &id);
if(r) {
if(result) *result = r;
vfs_icache_put(dir);
return 0;
}
// Step 4b: Read in that inode, and set some initial values (like creation time).
struct inode *node = vfs_icache_get(dir->filesystem, id);
if(!node) {
vfs_icache_put(dir);
if(result) *result = -EIO;
return 0;
}
node->mode = mode;
node->length = 0;
node->ctime = node->mtime = time_get_epoch();
vfs_inode_set_dirty(node);
// If we're making a directory, create the . and .. entries.
if(S_ISDIR(mode)) {
// Create . and ..
if(fs_link(node, node, ".", 1, true))
r = -EPERM;
if(fs_link(node, dir, "..", 2, true))
r = -EMLINK;
}
// Step 4c: Create the link for the directory entry to the inode.
r = fs_link(dir, node, name, strlen(name), false);
if(result)
*result = !r ? 1 : r;
if(dirent && !r) {
*dirent = fs_dirent_lookup(dir, name, strlen(name));
if(!*dirent && node) {
vfs_icache_put(node);
vfs_icache_put(dir);
if(result)
*result = -EIO;
return 0;
}
}
vfs_icache_put(dir);
return r ? 0 : node;
}
