qemu-patch-raspberry4/hw/file-op-9p.h
Sanchit Garg 56d15a5329 [virtio-9p] Use preadv/pwritev instead of readv/writev
readv & writev, read & write respectively from the current offset
of the file & hence their use has to be preceeded by a call to lseek.
preadv/writev can be used instead, as they take the offset as an argument.
This saves one system call( lseek ).
In case preadv is not supported, it is implemented by an lseek
followed by a readv. Depending upon the configuration of QEMU, the
appropriate read & write methods are selected. This patch also fixes the
zero byte read/write bug & obviates the need to apply a fix for that bug separately.

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Sanchit Garg <sancgarg@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
2010-10-20 12:10:59 -05:00

108 lines
3.1 KiB
C

/*
* Virtio 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 _FILEOP_H
#define _FILEOP_H
#include <sys/types.h>
#include <dirent.h>
#include <sys/time.h>
#include <utime.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <sys/vfs.h>
#define SM_LOCAL_MODE_BITS 0600
#define SM_LOCAL_DIR_MODE_BITS 0700
typedef enum
{
/*
* Server will try to set uid/gid.
* On failure ignore the error.
*/
SM_NONE = 0,
/*
* uid/gid set on fileserver files
*/
SM_PASSTHROUGH = 1,
/*
* uid/gid part of xattr
*/
SM_MAPPED,
} SecModel;
typedef struct FsCred
{
uid_t fc_uid;
gid_t fc_gid;
mode_t fc_mode;
dev_t fc_rdev;
} FsCred;
struct xattr_operations;
typedef struct FsContext
{
char *fs_root;
SecModel fs_sm;
uid_t uid;
struct xattr_operations **xops;
} FsContext;
extern void cred_init(FsCred *);
typedef struct FileOperations
{
int (*lstat)(FsContext *, const char *, struct stat *);
ssize_t (*readlink)(FsContext *, const char *, char *, size_t);
int (*chmod)(FsContext *, const char *, FsCred *);
int (*chown)(FsContext *, const char *, FsCred *);
int (*mknod)(FsContext *, const char *, FsCred *);
int (*utimensat)(FsContext *, const char *, const struct timespec *);
int (*remove)(FsContext *, const char *);
int (*symlink)(FsContext *, const char *, const char *, FsCred *);
int (*link)(FsContext *, const char *, const char *);
int (*setuid)(FsContext *, uid_t);
int (*close)(FsContext *, int);
int (*closedir)(FsContext *, DIR *);
DIR *(*opendir)(FsContext *, const char *);
int (*open)(FsContext *, const char *, int);
int (*open2)(FsContext *, const char *, int, FsCred *);
void (*rewinddir)(FsContext *, DIR *);
off_t (*telldir)(FsContext *, DIR *);
struct dirent *(*readdir)(FsContext *, DIR *);
void (*seekdir)(FsContext *, DIR *, off_t);
ssize_t (*preadv)(FsContext *, int, const struct iovec *, int, off_t);
ssize_t (*pwritev)(FsContext *, int, const struct iovec *, int, off_t);
int (*mkdir)(FsContext *, const char *, FsCred *);
int (*fstat)(FsContext *, int, struct stat *);
int (*rename)(FsContext *, const char *, const char *);
int (*truncate)(FsContext *, const char *, off_t);
int (*fsync)(FsContext *, int);
int (*statfs)(FsContext *s, const char *path, struct statfs *stbuf);
ssize_t (*lgetxattr)(FsContext *, const char *,
const char *, void *, size_t);
ssize_t (*llistxattr)(FsContext *, const char *, void *, size_t);
int (*lsetxattr)(FsContext *, const char *,
const char *, void *, size_t, int);
int (*lremovexattr)(FsContext *, const char *, const char *);
void *opaque;
} FileOperations;
static inline const char *rpath(FsContext *ctx, const char *path)
{
/* FIXME: so wrong... */
static char buffer[4096];
snprintf(buffer, sizeof(buffer), "%s/%s", ctx->fs_root, path);
return buffer;
}
#endif