qemu/fsdev/file-op-9p.h
Antonios Motakis 1a6ed33cc5 9p: Added virtfs option 'multidevs=remap|forbid|warn'
'warn' (default): Only log an error message (once) on host if more than one
device is shared by same export, except of that just ignore this config
error though. This is the default behaviour for not breaking existing
installations implying that they really know what they are doing.

'forbid': Like 'warn', but except of just logging an error this
also denies access of guest to additional devices.

'remap': Allows to share more than one device per export by remapping
inodes from host to guest appropriately. To support multiple devices on the
9p share, and avoid qid path collisions we take the device id as input to
generate a unique QID path. The lowest 48 bits of the path will be set
equal to the file inode, and the top bits will be uniquely assigned based
on the top 16 bits of the inode and the device id.

Signed-off-by: Antonios Motakis <antonios.motakis@huawei.com>
[CS: - Rebased to https://github.com/gkurz/qemu/commits/9p-next
       (SHA1 7fc4c49e91).
     - Added virtfs option 'multidevs', original patch simply did the inode
       remapping without being asked.
     - Updated hash calls to new xxhash API.
     - Updated docs for new option 'multidevs'.
     - Fixed v9fs_do_readdir() not having remapped inodes.
     - Log error message when running out of prefixes in
       qid_path_prefixmap().
     - Fixed definition of QPATH_INO_MASK.
     - Wrapped qpp_table initialization to dedicated qpp_table_init()
       function.
     - Dropped unnecessary parantheses in qpp_lookup_func().
     - Dropped unnecessary g_malloc0() result checks. ]
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
[groug: - Moved "multidevs" parsing to the local backend.
        - Added hint to invalid multidevs option error.
	- Turn "remap" into "x-remap". ]
Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:05 +02:00

158 lines
4.9 KiB
C

/*
* 9p
*
* Copyright IBM, Corp. 2010
*
* Authors:
* Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#ifndef FILE_OP_9P_H
#define FILE_OP_9P_H
#include <dirent.h>
#include <utime.h>
#include <sys/vfs.h>
#include "qemu-fsdev-throttle.h"
#define SM_LOCAL_MODE_BITS 0600
#define SM_LOCAL_DIR_MODE_BITS 0700
typedef struct FsCred {
uid_t fc_uid;
gid_t fc_gid;
mode_t fc_mode;
dev_t fc_rdev;
} FsCred;
typedef struct FsContext FsContext;
typedef struct V9fsPath V9fsPath;
typedef struct ExtendedOps {
int (*get_st_gen)(FsContext *, V9fsPath *, mode_t, uint64_t *);
} ExtendedOps;
/* export flags */
#define V9FS_IMMEDIATE_WRITEOUT 0x00000001
#define V9FS_PATHNAME_FSCONTEXT 0x00000002
/*
* uid/gid set on fileserver files
*/
#define V9FS_SM_PASSTHROUGH 0x00000004
/*
* uid/gid part of xattr
*/
#define V9FS_SM_MAPPED 0x00000008
/*
* Server will try to set uid/gid.
* On failure ignore the error.
*/
#define V9FS_SM_NONE 0x00000010
/*
* uid/gid part of .virtfs_meatadata namespace
*/
#define V9FS_SM_MAPPED_FILE 0x00000020
#define V9FS_RDONLY 0x00000040
#define V9FS_PROXY_SOCK_FD 0x00000080
#define V9FS_PROXY_SOCK_NAME 0x00000100
/*
* multidevs option (either one of the two applies exclusively)
*/
#define V9FS_REMAP_INODES 0x00000200
#define V9FS_FORBID_MULTIDEVS 0x00000400
#define V9FS_SEC_MASK 0x0000003C
typedef struct FileOperations FileOperations;
typedef struct XattrOperations XattrOperations;
/*
* Structure to store the various fsdev's passed through command line.
*/
typedef struct FsDriverEntry {
char *fsdev_id;
char *path;
int export_flags;
FileOperations *ops;
FsThrottle fst;
mode_t fmode;
mode_t dmode;
} FsDriverEntry;
struct FsContext {
uid_t uid;
char *fs_root;
int export_flags;
XattrOperations **xops;
ExtendedOps exops;
FsThrottle *fst;
/* fs driver specific data */
void *private;
mode_t fmode;
mode_t dmode;
};
struct V9fsPath {
uint16_t size;
char *data;
};
typedef union V9fsFidOpenState V9fsFidOpenState;
void cred_init(FsCred *);
struct FileOperations
{
int (*parse_opts)(QemuOpts *, FsDriverEntry *, Error **errp);
int (*init)(FsContext *, Error **errp);
void (*cleanup)(FsContext *);
int (*lstat)(FsContext *, V9fsPath *, struct stat *);
ssize_t (*readlink)(FsContext *, V9fsPath *, char *, size_t);
int (*chmod)(FsContext *, V9fsPath *, FsCred *);
int (*chown)(FsContext *, V9fsPath *, FsCred *);
int (*mknod)(FsContext *, V9fsPath *, const char *, FsCred *);
int (*utimensat)(FsContext *, V9fsPath *, const struct timespec *);
int (*remove)(FsContext *, const char *);
int (*symlink)(FsContext *, const char *, V9fsPath *,
const char *, FsCred *);
int (*link)(FsContext *, V9fsPath *, V9fsPath *, const char *);
int (*setuid)(FsContext *, uid_t);
int (*close)(FsContext *, V9fsFidOpenState *);
int (*closedir)(FsContext *, V9fsFidOpenState *);
int (*opendir)(FsContext *, V9fsPath *, V9fsFidOpenState *);
int (*open)(FsContext *, V9fsPath *, int, V9fsFidOpenState *);
int (*open2)(FsContext *, V9fsPath *, const char *,
int, FsCred *, V9fsFidOpenState *);
void (*rewinddir)(FsContext *, V9fsFidOpenState *);
off_t (*telldir)(FsContext *, V9fsFidOpenState *);
struct dirent * (*readdir)(FsContext *, V9fsFidOpenState *);
void (*seekdir)(FsContext *, V9fsFidOpenState *, off_t);
ssize_t (*preadv)(FsContext *, V9fsFidOpenState *,
const struct iovec *, int, off_t);
ssize_t (*pwritev)(FsContext *, V9fsFidOpenState *,
const struct iovec *, int, off_t);
int (*mkdir)(FsContext *, V9fsPath *, const char *, FsCred *);
int (*fstat)(FsContext *, int, V9fsFidOpenState *, struct stat *);
int (*rename)(FsContext *, const char *, const char *);
int (*truncate)(FsContext *, V9fsPath *, off_t);
int (*fsync)(FsContext *, int, V9fsFidOpenState *, int);
int (*statfs)(FsContext *s, V9fsPath *path, struct statfs *stbuf);
ssize_t (*lgetxattr)(FsContext *, V9fsPath *,
const char *, void *, size_t);
ssize_t (*llistxattr)(FsContext *, V9fsPath *, void *, size_t);
int (*lsetxattr)(FsContext *, V9fsPath *,
const char *, void *, size_t, int);
int (*lremovexattr)(FsContext *, V9fsPath *, const char *);
int (*name_to_path)(FsContext *, V9fsPath *, const char *, V9fsPath *);
int (*renameat)(FsContext *ctx, V9fsPath *olddir, const char *old_name,
V9fsPath *newdir, const char *new_name);
int (*unlinkat)(FsContext *ctx, V9fsPath *dir, const char *name, int flags);
};
#endif