root/headers/private/kernel/vfs.h
/*
 * Copyright 2002-2018, Axel Dörfler, axeld@pinc-software.de.
 * Distributed under the terms of the MIT License.
 *
 * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
 * Distributed under the terms of the NewOS License.
 */
#ifndef _KERNEL_VFS_H
#define _KERNEL_VFS_H


#include <kernel.h>
#include <lock.h>
#include <util/list.h>

#include <fs_interface.h>

#include <dirent.h>
#include <signal.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/select.h>

#include <vfs_defs.h>


#define DEFAULT_FD_TABLE_SIZE   256
#define MAX_FD_TABLE_SIZE               8192
#define DEFAULT_NODE_MONITORS   4096
#define MAX_NODE_MONITORS               65536

#define B_UNMOUNT_BUSY_PARTITION        0x80000000

struct attr_info;
struct file_descriptor;
struct generic_io_vec;
struct kernel_args;
struct net_stat;
struct pollfd;
struct rlimit;
struct selectsync;
struct select_info;
struct VMCache;
struct vnode;


/** The I/O context of a process/team, holds the fd array among others */
typedef struct io_context {
        struct vnode *root;

        mutable rw_lock lock;
        struct vnode *cwd;
        int32           ref_count;
        uint32          table_size;
        uint32          num_used_fds;
        struct file_descriptor **fds;
        struct select_info **select_infos;
        uint8           *fds_close_on_exec;
        uint8           *fds_close_on_fork;
        struct list node_monitors;
        uint32          num_monitors;
        uint32          max_monitors;
} io_context;


#ifdef __cplusplus
extern "C" {
#endif

status_t        vfs_init(struct kernel_args *args);
status_t        vfs_bootstrap_file_systems(void);
void            vfs_mount_boot_file_system(struct kernel_args *args);
void            vfs_exec_io_context(io_context *context);
io_context*     vfs_new_io_context(const io_context *parentContext,
                                bool purgeCloseOnExec);
void            vfs_get_io_context(io_context *context);
void            vfs_put_io_context(io_context *context);
status_t        vfs_resize_fd_table(struct io_context* context, uint32 newSize);

int                     vfs_getrlimit(int resource, struct rlimit *rlp);
int                     vfs_setrlimit(int resource, const struct rlimit *rlp);

/* calls needed by the VM for paging and by the file cache */
status_t        vfs_get_vnode_from_fd(int fd, bool kernel, struct vnode **_vnode);
status_t        vfs_get_vnode_from_path(const char *path, bool kernel,
                                struct vnode **_vnode);
status_t        vfs_get_vnode(dev_t mountID, ino_t vnodeID, bool canWait,
                                struct vnode **_vnode);
status_t        vfs_entry_ref_to_vnode(dev_t mountID, ino_t directoryID,
                                const char *name, struct vnode **_vnode);
void            vfs_vnode_to_node_ref(struct vnode *vnode, dev_t *_mountID,
                                ino_t *_vnodeID);
struct fs_vnode* vfs_fsnode_for_vnode(struct vnode* vnode);

int                     vfs_open_vnode(struct vnode* vnode, int openMode, bool kernel);
status_t        vfs_lookup_vnode(dev_t mountID, ino_t vnodeID,
                                struct vnode **_vnode);
void            vfs_put_vnode(struct vnode *vnode);
void            vfs_acquire_vnode(struct vnode *vnode);
status_t        vfs_get_cookie_from_fd(int fd, void **_cookie);
bool            vfs_can_page(struct vnode *vnode, void *cookie);
status_t        vfs_read_pages(struct vnode *vnode, void *cookie, off_t pos,
                                const struct generic_io_vec *vecs, size_t count, uint32 flags,
                                generic_size_t *_numBytes);
status_t        vfs_write_pages(struct vnode *vnode, void *cookie, off_t pos,
                                const struct generic_io_vec *vecs, size_t count, uint32 flags,
                                generic_size_t *_numBytes);
status_t        vfs_vnode_io(struct vnode* vnode, void* cookie,
                                io_request* request);
status_t        vfs_synchronous_io(io_request* request,
                                status_t (*doIO)(void* cookie, off_t offset, void* buffer,
                                        size_t* length),
                                void* cookie);
status_t        vfs_get_vnode_cache(struct vnode *vnode, struct VMCache **_cache,
                                bool allocate);
status_t        vfs_set_vnode_cache(struct vnode *vnode, struct VMCache *_cache);
status_t        vfs_get_file_map(struct vnode *vnode, off_t offset, size_t size,
                                struct file_io_vec *vecs, size_t *_count);
status_t        vfs_get_fs_node_from_path(fs_volume *volume, const char *path,
                                bool traverseLeafLink, bool kernel, void **_node);
status_t        vfs_stat_vnode(struct vnode *vnode, struct stat *stat);
status_t        vfs_stat_node_ref(dev_t device, ino_t inode, struct stat *stat);
status_t        vfs_get_vnode_name(struct vnode *vnode, char *name,
                                size_t nameSize);
status_t        vfs_entry_ref_to_path(dev_t device, ino_t inode, const char *leaf,
                                bool kernel, char *path, size_t pathLength);
status_t        vfs_get_cwd(dev_t *_mountID, ino_t *_vnodeID);
void            vfs_unlock_vnode_if_locked(struct file_descriptor *descriptor);
status_t        vfs_release_posix_lock(io_context* context,
                                struct file_descriptor* descriptor);
status_t        vfs_unmount(dev_t mountID, uint32 flags);
status_t        vfs_disconnect_vnode(dev_t mountID, ino_t vnodeID);
status_t        vfs_resolve_parent(struct vnode* parent, dev_t* device,
                                ino_t* node);
void            vfs_free_unused_vnodes(int32 level);

status_t        vfs_read_stat(int fd, const char *path, bool traverseLeafLink,
                                struct stat *stat, bool kernel);

/* special module convenience call */
status_t        vfs_get_module_path(const char *basePath, const char *moduleName,
                                char *pathBuffer, size_t bufferSize);

/* service call for whoever needs a normalized path */
status_t        vfs_normalize_path(const char *path, char *buffer,
                                size_t bufferSize, bool traverseLink, bool kernel);

/* service call for whoever wants to create a special node */
status_t        vfs_create_special_node(const char *path, fs_vnode *subVnode,
                                mode_t mode, uint32 flags, bool kernel, fs_vnode *_superVnode,
                                struct vnode **_createdVnode);

/* service call for the node monitor */
status_t        vfs_resolve_vnode_to_covering_vnode(dev_t mountID, ino_t nodeID,
                                dev_t *resolvedMountID, ino_t *resolvedNodeID);

/* service calls for private file systems */
status_t        vfs_get_mount_point(dev_t mountID, dev_t* _mountPointMountID,
                                ino_t* _mountPointNodeID);
status_t        vfs_bind_mount_directory(dev_t mountID, ino_t nodeID,
                                dev_t coveredMountID, ino_t coveredNodeID);

/* calls the syscall dispatcher should use for user file I/O */
dev_t           _user_mount(const char *path, const char *device,
                                const char *fs_name, uint32 flags, const char *args,
                                size_t argsLength);
status_t        _user_unmount(const char *path, uint32 flags);
status_t        _user_read_fs_info(dev_t device, struct fs_info *info);
status_t        _user_write_fs_info(dev_t device, const struct fs_info *info,
                                int mask);
dev_t           _user_next_device(int32 *_cookie);
status_t        _user_sync(void);
status_t        _user_get_next_fd_info(team_id team, uint32 *cookie,
                                struct fd_info *info, size_t infoSize);
status_t        _user_entry_ref_to_path(dev_t device, ino_t inode, const char *leaf,
                                char *userPath, size_t pathLength);
status_t        _user_normalize_path(const char* userPath, bool traverseLink,
                                char* buffer);
int                     _user_open_entry_ref(dev_t device, ino_t inode, const char *name,
                                int openMode, int perms);
int                     _user_open(int fd, const char *path, int openMode, int perms);
int                     _user_open_dir_node_ref(dev_t device, ino_t inode);
int                     _user_open_dir_entry_ref(dev_t device, ino_t inode,
                                const char *name);
int                     _user_open_dir(int fd, const char *path);
int                     _user_open_parent_dir(int fd, char *name, size_t nameLength);
status_t        _user_fcntl(int fd, int op, size_t argument);
status_t        _user_fsync(int fd, bool dataOnly);
status_t        _user_flock(int fd, int op);
status_t        _user_read_stat(int fd, const char *path, bool traverseLink,
                                struct stat *stat, size_t statSize);
status_t        _user_write_stat(int fd, const char *path, bool traverseLink,
                                const struct stat *stat, size_t statSize, int statMask);
off_t           _user_seek(int fd, off_t pos, int seekType);
status_t        _user_create_dir_entry_ref(dev_t device, ino_t inode,
                                const char *name, int perms);
status_t        _user_create_dir(int fd, const char *path, int perms);
status_t        _user_remove_dir(int fd, const char *path);
status_t        _user_read_link(int fd, const char *path, char *buffer,
                                size_t *_bufferSize);
status_t        _user_write_link(const char *path, const char *toPath);
status_t        _user_create_symlink(int fd, const char *path, const char *toPath,
                                int mode);
status_t        _user_create_link(int pathFD, const char *path, int toFD,
                                const char *toPath, bool traverseLeafLink);
status_t        _user_unlink(int fd, const char *path);
status_t        _user_rename(int oldFD, const char *oldpath, int newFD,
                                const char *newpath);
status_t        _user_create_fifo(int fd, const char *path, mode_t perms);
status_t        _user_create_pipe(int *fds, int flags);
status_t        _user_access(int fd, const char *path, int mode,
                                bool effectiveUserGroup);
ssize_t         _user_select(int numfds, fd_set *readSet, fd_set *writeSet,
                                fd_set *errorSet, bigtime_t timeout, const sigset_t *sigMask);
ssize_t         _user_poll(struct pollfd *fds, int numfds, bigtime_t timeout,
                                const sigset_t *sigMask);
int                     _user_open_attr_dir(int fd, const char *path,
                                bool traverseLeafLink);
ssize_t         _user_read_attr(int fd, const char *attribute, off_t pos,
                                void *buffer, size_t readBytes);
ssize_t         _user_write_attr(int fd, const char *attribute, uint32 type,
                                off_t pos, const void *buffer, size_t readBytes);
status_t        _user_stat_attr(int fd, const char *attribute,
                                struct attr_info *attrInfo);
int                     _user_open_attr(int fd, const char* path, const char *name,
                                uint32 type, int openMode);
status_t        _user_remove_attr(int fd, const char *name);
status_t        _user_rename_attr(int fromFile, const char *fromName, int toFile,
                                const char *toName);
int                     _user_open_index_dir(dev_t device);
status_t        _user_create_index(dev_t device, const char *name, uint32 type,
                                uint32 flags);
status_t        _user_read_index_stat(dev_t device, const char *name,
                                struct stat *stat);
status_t        _user_remove_index(dev_t device, const char *name);
status_t        _user_getcwd(char *buffer, size_t size);
status_t        _user_setcwd(int fd, const char *path);
status_t        _user_change_root(const char *path);
int                     _user_open_query(dev_t device, const char *query,
                                size_t queryLength, uint32 flags, port_id port, int32 token);

/* fd user prototypes (implementation located in fd.cpp)  */
ssize_t         _user_read(int fd, off_t pos, void *buffer, size_t bufferSize);
ssize_t         _user_readv(int fd, off_t pos, const iovec *vecs, size_t count);
ssize_t         _user_write(int fd, off_t pos, const void *buffer,
                                size_t bufferSize);
ssize_t         _user_writev(int fd, off_t pos, const iovec *vecs, size_t count);
status_t        _user_ioctl(int fd, uint32 cmd, void *data, size_t length);
ssize_t         _user_read_dir(int fd, struct dirent *buffer, size_t bufferSize,
                                uint32 maxCount);
status_t        _user_rewind_dir(int fd);
status_t        _user_close(int fd);
int                     _user_dup(int fd);
int                     _user_dup2(int ofd, int nfd, int flags);
status_t        _user_lock_node(int fd);
status_t        _user_unlock_node(int fd);
status_t        _user_preallocate(int fd, off_t offset, off_t length);
status_t        _user_close_range(u_int minFd, u_int maxFd, int flags);

/* socket user prototypes (implementation in socket.cpp) */
int                     _user_socket(int family, int type, int protocol);
status_t        _user_bind(int socket, const struct sockaddr *address,
                                socklen_t addressLength);
status_t        _user_shutdown_socket(int socket, int how);
status_t        _user_connect(int socket, const struct sockaddr *address,
                                socklen_t addressLength);
status_t        _user_listen(int socket, int backlog);
int                     _user_accept(int socket, struct sockaddr *address,
                                socklen_t *_addressLength, int flags);
ssize_t         _user_recv(int socket, void *data, size_t length, int flags);
ssize_t         _user_recvfrom(int socket, void *data, size_t length, int flags,
                                struct sockaddr *address, socklen_t *_addressLength);
ssize_t         _user_recvmsg(int socket, struct msghdr *message, int flags);
ssize_t         _user_send(int socket, const void *data, size_t length, int flags);
ssize_t         _user_sendto(int socket, const void *data, size_t length, int flags,
                                const struct sockaddr *address, socklen_t addressLength);
ssize_t         _user_sendmsg(int socket, const struct msghdr *message, int flags);
status_t        _user_getsockopt(int socket, int level, int option, void *value,
                                socklen_t *_length);
status_t        _user_setsockopt(int socket, int level, int option,
                                const void *value, socklen_t length);
status_t        _user_getpeername(int socket, struct sockaddr *address,
                                socklen_t *_addressLength);
status_t        _user_getsockname(int socket, struct sockaddr *address,
                                socklen_t *_addressLength);
int                     _user_sockatmark(int socket);
status_t        _user_socketpair(int family, int type, int protocol,
                                int *socketVector);
status_t        _user_get_next_socket_stat(int family, uint32 *cookie,
                                struct net_stat *stat);

#ifdef __cplusplus
}
#endif


#ifdef __cplusplus

class AsyncIOCallback {
public:
        virtual                                         ~AsyncIOCallback();

        virtual void                            IOFinished(status_t status,
                                                                        bool partialTransfer,
                                                                        generic_size_t bytesTransferred) = 0;

        static  void                            IORequestCallback(void* data,
                                                                        io_request* request, status_t status,
                                                                        bool partialTransfer,
                                                                        generic_size_t bytesTransferred);
};


class StackableAsyncIOCallback : public AsyncIOCallback {
public:
                                                                StackableAsyncIOCallback(AsyncIOCallback* next);

protected:
                        AsyncIOCallback*        fNextCallback;
};


status_t        vfs_asynchronous_read_pages(struct vnode* vnode, void* cookie,
                                off_t pos, const struct generic_io_vec* vecs, size_t count,
                                generic_size_t numBytes, uint32 flags,
                                AsyncIOCallback* callback);

status_t        vfs_asynchronous_write_pages(struct vnode* vnode, void* cookie,
                                off_t pos, const struct generic_io_vec* vecs, size_t count,
                                generic_size_t numBytes, uint32 flags,
                                AsyncIOCallback* callback);

#endif  // __cplusplus

#endif  /* _KERNEL_VFS_H */