qemu/hw/virtio-9p.c
Anthony Liguori bb9e3216bf virtio-9p: Add stat and mode related helper functions.
Add helpers to obtain file stat and mode details.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-05-03 12:17:38 -05:00

1026 lines
24 KiB
C

/*
* Virtio 9p backend
*
* Copyright IBM, Corp. 2010
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include "virtio.h"
#include "pc.h"
#include "qemu_socket.h"
#include "virtio-9p.h"
#include "fsdev/qemu-fsdev.h"
#include "virtio-9p-debug.h"
int dotu = 1;
int debug_9p_pdu;
static int v9fs_do_lstat(V9fsState *s, V9fsString *path, struct stat *stbuf)
{
return s->ops->lstat(&s->ctx, path->data, stbuf);
}
static int v9fs_do_setuid(V9fsState *s, uid_t uid)
{
return s->ops->setuid(&s->ctx, uid);
}
static ssize_t v9fs_do_readlink(V9fsState *s, V9fsString *path, V9fsString *buf)
{
ssize_t len;
buf->data = qemu_malloc(1024);
len = s->ops->readlink(&s->ctx, path->data, buf->data, 1024 - 1);
if (len > -1) {
buf->size = len;
buf->data[len] = 0;
}
return len;
}
static int v9fs_do_close(V9fsState *s, int fd)
{
return s->ops->close(&s->ctx, fd);
}
static int v9fs_do_closedir(V9fsState *s, DIR *dir)
{
return s->ops->closedir(&s->ctx, dir);
}
static void v9fs_string_init(V9fsString *str)
{
str->data = NULL;
str->size = 0;
}
static void v9fs_string_free(V9fsString *str)
{
qemu_free(str->data);
str->data = NULL;
str->size = 0;
}
static void v9fs_string_null(V9fsString *str)
{
v9fs_string_free(str);
}
static int number_to_string(void *arg, char type)
{
unsigned int ret = 0;
switch (type) {
case 'u': {
unsigned int num = *(unsigned int *)arg;
do {
ret++;
num = num/10;
} while (num);
break;
}
default:
printf("Number_to_string: Unknown number format\n");
return -1;
}
return ret;
}
static int v9fs_string_alloc_printf(char **strp, const char *fmt, va_list ap)
{
va_list ap2;
char *iter = (char *)fmt;
int len = 0;
int nr_args = 0;
char *arg_char_ptr;
unsigned int arg_uint;
/* Find the number of %'s that denotes an argument */
for (iter = strstr(iter, "%"); iter; iter = strstr(iter, "%")) {
nr_args++;
iter++;
}
len = strlen(fmt) - 2*nr_args;
if (!nr_args) {
goto alloc_print;
}
va_copy(ap2, ap);
iter = (char *)fmt;
/* Now parse the format string */
for (iter = strstr(iter, "%"); iter; iter = strstr(iter, "%")) {
iter++;
switch (*iter) {
case 'u':
arg_uint = va_arg(ap2, unsigned int);
len += number_to_string((void *)&arg_uint, 'u');
break;
case 's':
arg_char_ptr = va_arg(ap2, char *);
len += strlen(arg_char_ptr);
break;
case 'c':
len += 1;
break;
default:
fprintf(stderr,
"v9fs_string_alloc_printf:Incorrect format %c", *iter);
return -1;
}
iter++;
}
alloc_print:
*strp = qemu_malloc((len + 1) * sizeof(**strp));
return vsprintf(*strp, fmt, ap);
}
static void v9fs_string_sprintf(V9fsString *str, const char *fmt, ...)
{
va_list ap;
int err;
v9fs_string_free(str);
va_start(ap, fmt);
err = v9fs_string_alloc_printf(&str->data, fmt, ap);
BUG_ON(err == -1);
va_end(ap);
str->size = err;
}
static void v9fs_string_copy(V9fsString *lhs, V9fsString *rhs)
{
v9fs_string_free(lhs);
v9fs_string_sprintf(lhs, "%s", rhs->data);
}
static size_t v9fs_string_size(V9fsString *str)
{
return str->size;
}
static V9fsFidState *lookup_fid(V9fsState *s, int32_t fid)
{
V9fsFidState *f;
for (f = s->fid_list; f; f = f->next) {
if (f->fid == fid) {
v9fs_do_setuid(s, f->uid);
return f;
}
}
return NULL;
}
static V9fsFidState *alloc_fid(V9fsState *s, int32_t fid)
{
V9fsFidState *f;
f = lookup_fid(s, fid);
if (f) {
return NULL;
}
f = qemu_mallocz(sizeof(V9fsFidState));
f->fid = fid;
f->fd = -1;
f->dir = NULL;
f->next = s->fid_list;
s->fid_list = f;
return f;
}
static int free_fid(V9fsState *s, int32_t fid)
{
V9fsFidState **fidpp, *fidp;
for (fidpp = &s->fid_list; *fidpp; fidpp = &(*fidpp)->next) {
if ((*fidpp)->fid == fid) {
break;
}
}
if (*fidpp == NULL) {
return -ENOENT;
}
fidp = *fidpp;
*fidpp = fidp->next;
if (fidp->fd != -1) {
v9fs_do_close(s, fidp->fd);
}
if (fidp->dir) {
v9fs_do_closedir(s, fidp->dir);
}
v9fs_string_free(&fidp->path);
qemu_free(fidp);
return 0;
}
#define P9_QID_TYPE_DIR 0x80
#define P9_QID_TYPE_SYMLINK 0x02
#define P9_STAT_MODE_DIR 0x80000000
#define P9_STAT_MODE_APPEND 0x40000000
#define P9_STAT_MODE_EXCL 0x20000000
#define P9_STAT_MODE_MOUNT 0x10000000
#define P9_STAT_MODE_AUTH 0x08000000
#define P9_STAT_MODE_TMP 0x04000000
#define P9_STAT_MODE_SYMLINK 0x02000000
#define P9_STAT_MODE_LINK 0x01000000
#define P9_STAT_MODE_DEVICE 0x00800000
#define P9_STAT_MODE_NAMED_PIPE 0x00200000
#define P9_STAT_MODE_SOCKET 0x00100000
#define P9_STAT_MODE_SETUID 0x00080000
#define P9_STAT_MODE_SETGID 0x00040000
#define P9_STAT_MODE_SETVTX 0x00010000
#define P9_STAT_MODE_TYPE_BITS (P9_STAT_MODE_DIR | \
P9_STAT_MODE_SYMLINK | \
P9_STAT_MODE_LINK | \
P9_STAT_MODE_DEVICE | \
P9_STAT_MODE_NAMED_PIPE | \
P9_STAT_MODE_SOCKET)
/* This is the algorithm from ufs in spfs */
static void stat_to_qid(const struct stat *stbuf, V9fsQID *qidp)
{
size_t size;
size = MIN(sizeof(stbuf->st_ino), sizeof(qidp->path));
memcpy(&qidp->path, &stbuf->st_ino, size);
qidp->version = stbuf->st_mtime ^ (stbuf->st_size << 8);
qidp->type = 0;
if (S_ISDIR(stbuf->st_mode)) {
qidp->type |= P9_QID_TYPE_DIR;
}
if (S_ISLNK(stbuf->st_mode)) {
qidp->type |= P9_QID_TYPE_SYMLINK;
}
}
static int fid_to_qid(V9fsState *s, V9fsFidState *fidp, V9fsQID *qidp)
{
struct stat stbuf;
int err;
err = v9fs_do_lstat(s, &fidp->path, &stbuf);
if (err) {
return err;
}
stat_to_qid(&stbuf, qidp);
return 0;
}
static V9fsPDU *alloc_pdu(V9fsState *s)
{
V9fsPDU *pdu = NULL;
if (!QLIST_EMPTY(&s->free_list)) {
pdu = QLIST_FIRST(&s->free_list);
QLIST_REMOVE(pdu, next);
}
return pdu;
}
static void free_pdu(V9fsState *s, V9fsPDU *pdu)
{
if (pdu) {
QLIST_INSERT_HEAD(&s->free_list, pdu, next);
}
}
size_t pdu_packunpack(void *addr, struct iovec *sg, int sg_count,
size_t offset, size_t size, int pack)
{
int i = 0;
size_t copied = 0;
for (i = 0; size && i < sg_count; i++) {
size_t len;
if (offset >= sg[i].iov_len) {
/* skip this sg */
offset -= sg[i].iov_len;
continue;
} else {
len = MIN(sg[i].iov_len - offset, size);
if (pack) {
memcpy(sg[i].iov_base + offset, addr, len);
} else {
memcpy(addr, sg[i].iov_base + offset, len);
}
size -= len;
copied += len;
addr += len;
if (size) {
offset = 0;
continue;
}
}
}
return copied;
}
static size_t pdu_unpack(void *dst, V9fsPDU *pdu, size_t offset, size_t size)
{
return pdu_packunpack(dst, pdu->elem.out_sg, pdu->elem.out_num,
offset, size, 0);
}
static size_t pdu_pack(V9fsPDU *pdu, size_t offset, const void *src,
size_t size)
{
return pdu_packunpack((void *)src, pdu->elem.in_sg, pdu->elem.in_num,
offset, size, 1);
}
static int pdu_copy_sg(V9fsPDU *pdu, size_t offset, int rx, struct iovec *sg)
{
size_t pos = 0;
int i, j;
struct iovec *src_sg;
unsigned int num;
if (rx) {
src_sg = pdu->elem.in_sg;
num = pdu->elem.in_num;
} else {
src_sg = pdu->elem.out_sg;
num = pdu->elem.out_num;
}
j = 0;
for (i = 0; i < num; i++) {
if (offset <= pos) {
sg[j].iov_base = src_sg[i].iov_base;
sg[j].iov_len = src_sg[i].iov_len;
j++;
} else if (offset < (src_sg[i].iov_len + pos)) {
sg[j].iov_base = src_sg[i].iov_base;
sg[j].iov_len = src_sg[i].iov_len;
sg[j].iov_base += (offset - pos);
sg[j].iov_len -= (offset - pos);
j++;
}
pos += src_sg[i].iov_len;
}
return j;
}
static size_t pdu_unmarshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...)
{
size_t old_offset = offset;
va_list ap;
int i;
va_start(ap, fmt);
for (i = 0; fmt[i]; i++) {
switch (fmt[i]) {
case 'b': {
uint8_t *valp = va_arg(ap, uint8_t *);
offset += pdu_unpack(valp, pdu, offset, sizeof(*valp));
break;
}
case 'w': {
uint16_t val, *valp;
valp = va_arg(ap, uint16_t *);
val = le16_to_cpupu(valp);
offset += pdu_unpack(&val, pdu, offset, sizeof(val));
*valp = val;
break;
}
case 'd': {
uint32_t val, *valp;
valp = va_arg(ap, uint32_t *);
val = le32_to_cpupu(valp);
offset += pdu_unpack(&val, pdu, offset, sizeof(val));
*valp = val;
break;
}
case 'q': {
uint64_t val, *valp;
valp = va_arg(ap, uint64_t *);
val = le64_to_cpup(valp);
offset += pdu_unpack(&val, pdu, offset, sizeof(val));
*valp = val;
break;
}
case 'v': {
struct iovec *iov = va_arg(ap, struct iovec *);
int *iovcnt = va_arg(ap, int *);
*iovcnt = pdu_copy_sg(pdu, offset, 0, iov);
break;
}
case 's': {
V9fsString *str = va_arg(ap, V9fsString *);
offset += pdu_unmarshal(pdu, offset, "w", &str->size);
/* FIXME: sanity check str->size */
str->data = qemu_malloc(str->size + 1);
offset += pdu_unpack(str->data, pdu, offset, str->size);
str->data[str->size] = 0;
break;
}
case 'Q': {
V9fsQID *qidp = va_arg(ap, V9fsQID *);
offset += pdu_unmarshal(pdu, offset, "bdq",
&qidp->type, &qidp->version, &qidp->path);
break;
}
case 'S': {
V9fsStat *statp = va_arg(ap, V9fsStat *);
offset += pdu_unmarshal(pdu, offset, "wwdQdddqsssssddd",
&statp->size, &statp->type, &statp->dev,
&statp->qid, &statp->mode, &statp->atime,
&statp->mtime, &statp->length,
&statp->name, &statp->uid, &statp->gid,
&statp->muid, &statp->extension,
&statp->n_uid, &statp->n_gid,
&statp->n_muid);
break;
}
default:
break;
}
}
va_end(ap);
return offset - old_offset;
}
static size_t pdu_marshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...)
{
size_t old_offset = offset;
va_list ap;
int i;
va_start(ap, fmt);
for (i = 0; fmt[i]; i++) {
switch (fmt[i]) {
case 'b': {
uint8_t val = va_arg(ap, int);
offset += pdu_pack(pdu, offset, &val, sizeof(val));
break;
}
case 'w': {
uint16_t val;
cpu_to_le16w(&val, va_arg(ap, int));
offset += pdu_pack(pdu, offset, &val, sizeof(val));
break;
}
case 'd': {
uint32_t val;
cpu_to_le32w(&val, va_arg(ap, uint32_t));
offset += pdu_pack(pdu, offset, &val, sizeof(val));
break;
}
case 'q': {
uint64_t val;
cpu_to_le64w(&val, va_arg(ap, uint64_t));
offset += pdu_pack(pdu, offset, &val, sizeof(val));
break;
}
case 'v': {
struct iovec *iov = va_arg(ap, struct iovec *);
int *iovcnt = va_arg(ap, int *);
*iovcnt = pdu_copy_sg(pdu, offset, 1, iov);
break;
}
case 's': {
V9fsString *str = va_arg(ap, V9fsString *);
offset += pdu_marshal(pdu, offset, "w", str->size);
offset += pdu_pack(pdu, offset, str->data, str->size);
break;
}
case 'Q': {
V9fsQID *qidp = va_arg(ap, V9fsQID *);
offset += pdu_marshal(pdu, offset, "bdq",
qidp->type, qidp->version, qidp->path);
break;
}
case 'S': {
V9fsStat *statp = va_arg(ap, V9fsStat *);
offset += pdu_marshal(pdu, offset, "wwdQdddqsssssddd",
statp->size, statp->type, statp->dev,
&statp->qid, statp->mode, statp->atime,
statp->mtime, statp->length, &statp->name,
&statp->uid, &statp->gid, &statp->muid,
&statp->extension, statp->n_uid,
statp->n_gid, statp->n_muid);
break;
}
default:
break;
}
}
va_end(ap);
return offset - old_offset;
}
static void complete_pdu(V9fsState *s, V9fsPDU *pdu, ssize_t len)
{
int8_t id = pdu->id + 1; /* Response */
if (len < 0) {
V9fsString str;
int err = -len;
str.data = strerror(err);
str.size = strlen(str.data);
len = 7;
len += pdu_marshal(pdu, len, "s", &str);
if (dotu) {
len += pdu_marshal(pdu, len, "d", err);
}
id = P9_RERROR;
}
/* fill out the header */
pdu_marshal(pdu, 0, "dbw", (int32_t)len, id, pdu->tag);
/* keep these in sync */
pdu->size = len;
pdu->id = id;
/* push onto queue and notify */
virtqueue_push(s->vq, &pdu->elem, len);
/* FIXME: we should batch these completions */
virtio_notify(&s->vdev, s->vq);
free_pdu(s, pdu);
}
static mode_t v9mode_to_mode(uint32_t mode, V9fsString *extension)
{
mode_t ret;
ret = mode & 0777;
if (mode & P9_STAT_MODE_DIR) {
ret |= S_IFDIR;
}
if (dotu) {
if (mode & P9_STAT_MODE_SYMLINK) {
ret |= S_IFLNK;
}
if (mode & P9_STAT_MODE_SOCKET) {
ret |= S_IFSOCK;
}
if (mode & P9_STAT_MODE_NAMED_PIPE) {
ret |= S_IFIFO;
}
if (mode & P9_STAT_MODE_DEVICE) {
if (extension && extension->data[0] == 'c') {
ret |= S_IFCHR;
} else {
ret |= S_IFBLK;
}
}
}
if (!(ret&~0777)) {
ret |= S_IFREG;
}
if (mode & P9_STAT_MODE_SETUID) {
ret |= S_ISUID;
}
if (mode & P9_STAT_MODE_SETGID) {
ret |= S_ISGID;
}
if (mode & P9_STAT_MODE_SETVTX) {
ret |= S_ISVTX;
}
return ret;
}
static int donttouch_stat(V9fsStat *stat)
{
if (stat->type == -1 &&
stat->dev == -1 &&
stat->qid.type == -1 &&
stat->qid.version == -1 &&
stat->qid.path == -1 &&
stat->mode == -1 &&
stat->atime == -1 &&
stat->mtime == -1 &&
stat->length == -1 &&
!stat->name.size &&
!stat->uid.size &&
!stat->gid.size &&
!stat->muid.size &&
stat->n_uid == -1 &&
stat->n_gid == -1 &&
stat->n_muid == -1) {
return 1;
}
return 0;
}
static void v9fs_stat_free(V9fsStat *stat)
{
v9fs_string_free(&stat->name);
v9fs_string_free(&stat->uid);
v9fs_string_free(&stat->gid);
v9fs_string_free(&stat->muid);
v9fs_string_free(&stat->extension);
}
static uint32_t stat_to_v9mode(const struct stat *stbuf)
{
uint32_t mode;
mode = stbuf->st_mode & 0777;
if (S_ISDIR(stbuf->st_mode)) {
mode |= P9_STAT_MODE_DIR;
}
if (dotu) {
if (S_ISLNK(stbuf->st_mode)) {
mode |= P9_STAT_MODE_SYMLINK;
}
if (S_ISSOCK(stbuf->st_mode)) {
mode |= P9_STAT_MODE_SOCKET;
}
if (S_ISFIFO(stbuf->st_mode)) {
mode |= P9_STAT_MODE_NAMED_PIPE;
}
if (S_ISBLK(stbuf->st_mode) || S_ISCHR(stbuf->st_mode)) {
mode |= P9_STAT_MODE_DEVICE;
}
if (stbuf->st_mode & S_ISUID) {
mode |= P9_STAT_MODE_SETUID;
}
if (stbuf->st_mode & S_ISGID) {
mode |= P9_STAT_MODE_SETGID;
}
if (stbuf->st_mode & S_ISVTX) {
mode |= P9_STAT_MODE_SETVTX;
}
}
return mode;
}
static int stat_to_v9stat(V9fsState *s, V9fsString *name,
const struct stat *stbuf,
V9fsStat *v9stat)
{
int err;
const char *str;
memset(v9stat, 0, sizeof(*v9stat));
stat_to_qid(stbuf, &v9stat->qid);
v9stat->mode = stat_to_v9mode(stbuf);
v9stat->atime = stbuf->st_atime;
v9stat->mtime = stbuf->st_mtime;
v9stat->length = stbuf->st_size;
v9fs_string_null(&v9stat->uid);
v9fs_string_null(&v9stat->gid);
v9fs_string_null(&v9stat->muid);
if (dotu) {
v9stat->n_uid = stbuf->st_uid;
v9stat->n_gid = stbuf->st_gid;
v9stat->n_muid = 0;
v9fs_string_null(&v9stat->extension);
if (v9stat->mode & P9_STAT_MODE_SYMLINK) {
err = v9fs_do_readlink(s, name, &v9stat->extension);
if (err == -1) {
err = -errno;
return err;
}
v9stat->extension.data[err] = 0;
v9stat->extension.size = err;
} else if (v9stat->mode & P9_STAT_MODE_DEVICE) {
v9fs_string_sprintf(&v9stat->extension, "%c %u %u",
S_ISCHR(stbuf->st_mode) ? 'c' : 'b',
major(stbuf->st_rdev), minor(stbuf->st_rdev));
} else if (S_ISDIR(stbuf->st_mode) || S_ISREG(stbuf->st_mode)) {
v9fs_string_sprintf(&v9stat->extension, "%s %u",
"HARDLINKCOUNT", stbuf->st_nlink);
}
}
str = strrchr(name->data, '/');
if (str) {
str += 1;
} else {
str = name->data;
}
v9fs_string_sprintf(&v9stat->name, "%s", str);
v9stat->size = 61 +
v9fs_string_size(&v9stat->name) +
v9fs_string_size(&v9stat->uid) +
v9fs_string_size(&v9stat->gid) +
v9fs_string_size(&v9stat->muid) +
v9fs_string_size(&v9stat->extension);
return 0;
}
static void v9fs_dummy(V9fsState *s, V9fsPDU *pdu)
{
/* Note: The following have been added to prevent GCC from complaining
* They will be removed in the subsequent patches */
(void)pdu_unmarshal;
(void) complete_pdu;
(void) v9fs_string_init;
(void) v9fs_string_free;
(void) v9fs_string_null;
(void) v9fs_string_sprintf;
(void) v9fs_string_copy;
(void) v9fs_string_size;
(void) v9fs_do_lstat;
(void) v9fs_do_setuid;
(void) v9fs_do_readlink;
(void) v9fs_do_close;
(void) v9fs_do_closedir;
(void) alloc_fid;
(void) free_fid;
(void) fid_to_qid;
(void) v9mode_to_mode;
(void) donttouch_stat;
(void) v9fs_stat_free;
(void) stat_to_v9stat;
}
static void v9fs_version(V9fsState *s, V9fsPDU *pdu)
{
if (debug_9p_pdu) {
pprint_pdu(pdu);
}
}
static void v9fs_attach(V9fsState *s, V9fsPDU *pdu)
{
if (debug_9p_pdu) {
pprint_pdu(pdu);
}
}
static void v9fs_stat(V9fsState *s, V9fsPDU *pdu)
{
if (debug_9p_pdu) {
pprint_pdu(pdu);
}
}
static void v9fs_walk(V9fsState *s, V9fsPDU *pdu)
{
if (debug_9p_pdu) {
pprint_pdu(pdu);
}
}
static void v9fs_clunk(V9fsState *s, V9fsPDU *pdu)
{
if (debug_9p_pdu) {
pprint_pdu(pdu);
}
}
static void v9fs_open(V9fsState *s, V9fsPDU *pdu)
{ if (debug_9p_pdu) {
pprint_pdu(pdu);
}
}
static void v9fs_read(V9fsState *s, V9fsPDU *pdu)
{
if (debug_9p_pdu) {
pprint_pdu(pdu);
}
}
static void v9fs_write(V9fsState *s, V9fsPDU *pdu)
{
if (debug_9p_pdu) {
pprint_pdu(pdu);
}
}
static void v9fs_create(V9fsState *s, V9fsPDU *pdu)
{
if (debug_9p_pdu) {
pprint_pdu(pdu);
}
}
static void v9fs_flush(V9fsState *s, V9fsPDU *pdu)
{
v9fs_dummy(s, pdu);
if (debug_9p_pdu) {
pprint_pdu(pdu);
}
}
static void v9fs_remove(V9fsState *s, V9fsPDU *pdu)
{
if (debug_9p_pdu) {
pprint_pdu(pdu);
}
}
static void v9fs_wstat(V9fsState *s, V9fsPDU *pdu)
{
if (debug_9p_pdu) {
pprint_pdu(pdu);
}
}
typedef void (pdu_handler_t)(V9fsState *s, V9fsPDU *pdu);
static pdu_handler_t *pdu_handlers[] = {
[P9_TVERSION] = v9fs_version,
[P9_TATTACH] = v9fs_attach,
[P9_TSTAT] = v9fs_stat,
[P9_TWALK] = v9fs_walk,
[P9_TCLUNK] = v9fs_clunk,
[P9_TOPEN] = v9fs_open,
[P9_TREAD] = v9fs_read,
#if 0
[P9_TAUTH] = v9fs_auth,
#endif
[P9_TFLUSH] = v9fs_flush,
[P9_TCREATE] = v9fs_create,
[P9_TWRITE] = v9fs_write,
[P9_TWSTAT] = v9fs_wstat,
[P9_TREMOVE] = v9fs_remove,
};
static void submit_pdu(V9fsState *s, V9fsPDU *pdu)
{
pdu_handler_t *handler;
if (debug_9p_pdu) {
pprint_pdu(pdu);
}
BUG_ON(pdu->id >= ARRAY_SIZE(pdu_handlers));
handler = pdu_handlers[pdu->id];
BUG_ON(handler == NULL);
handler(s, pdu);
}
static void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq)
{
V9fsState *s = (V9fsState *)vdev;
V9fsPDU *pdu;
ssize_t len;
while ((pdu = alloc_pdu(s)) &&
(len = virtqueue_pop(vq, &pdu->elem)) != 0) {
uint8_t *ptr;
BUG_ON(pdu->elem.out_num == 0 || pdu->elem.in_num == 0);
BUG_ON(pdu->elem.out_sg[0].iov_len < 7);
ptr = pdu->elem.out_sg[0].iov_base;
memcpy(&pdu->size, ptr, 4);
pdu->id = ptr[4];
memcpy(&pdu->tag, ptr + 5, 2);
submit_pdu(s, pdu);
}
free_pdu(s, pdu);
}
static uint32_t virtio_9p_get_features(VirtIODevice *vdev, uint32_t features)
{
features |= 1 << VIRTIO_9P_MOUNT_TAG;
return features;
}
static V9fsState *to_virtio_9p(VirtIODevice *vdev)
{
return (V9fsState *)vdev;
}
static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
{
struct virtio_9p_config *cfg;
V9fsState *s = to_virtio_9p(vdev);
cfg = qemu_mallocz(sizeof(struct virtio_9p_config) +
s->tag_len);
stw_raw(&cfg->tag_len, s->tag_len);
memcpy(cfg->tag, s->tag, s->tag_len);
memcpy(config, cfg, s->config_size);
qemu_free(cfg);
}
VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf)
{
V9fsState *s;
int i, len;
struct stat stat;
FsTypeEntry *fse;
s = (V9fsState *)virtio_common_init("virtio-9p",
VIRTIO_ID_9P,
sizeof(struct virtio_9p_config)+
MAX_TAG_LEN,
sizeof(V9fsState));
/* initialize pdu allocator */
QLIST_INIT(&s->free_list);
for (i = 0; i < (MAX_REQ - 1); i++) {
QLIST_INSERT_HEAD(&s->free_list, &s->pdus[i], next);
}
s->vq = virtio_add_queue(&s->vdev, MAX_REQ, handle_9p_output);
fse = get_fsdev_fsentry(conf->fsdev_id);
if (!fse) {
/* We don't have a fsdev identified by fsdev_id */
fprintf(stderr, "Virtio-9p device couldn't find fsdev "
"with the id %s\n", conf->fsdev_id);
exit(1);
}
if (!fse->path || !conf->tag) {
/* we haven't specified a mount_tag or the path */
fprintf(stderr, "fsdev with id %s needs path "
"and Virtio-9p device needs mount_tag arguments\n",
conf->fsdev_id);
exit(1);
}
if (lstat(fse->path, &stat)) {
fprintf(stderr, "share path %s does not exist\n", fse->path);
exit(1);
} else if (!S_ISDIR(stat.st_mode)) {
fprintf(stderr, "share path %s is not a directory \n", fse->path);
exit(1);
}
s->ctx.fs_root = qemu_strdup(fse->path);
len = strlen(conf->tag);
if (len > MAX_TAG_LEN) {
len = MAX_TAG_LEN;
}
/* s->tag is non-NULL terminated string */
s->tag = qemu_malloc(len);
memcpy(s->tag, conf->tag, len);
s->tag_len = len;
s->ctx.uid = -1;
s->ops = fse->ops;
s->vdev.get_features = virtio_9p_get_features;
s->config_size = sizeof(struct virtio_9p_config) +
s->tag_len;
s->vdev.get_config = virtio_9p_get_config;
return &s->vdev;
}