qemu/hw/9pfs/cofs.c

372 lines
9.0 KiB
C

/*
* 9p backend
*
* Copyright IBM, Corp. 2011
*
* 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.
*
*/
#include "qemu/osdep.h"
#include "fsdev/qemu-fsdev.h"
#include "qemu/thread.h"
#include "qemu/coroutine.h"
#include "coth.h"
static ssize_t __readlink(V9fsState *s, V9fsPath *path, V9fsString *buf)
{
ssize_t len, maxlen = PATH_MAX;
buf->data = g_malloc(PATH_MAX);
for(;;) {
len = s->ops->readlink(&s->ctx, path, buf->data, maxlen);
if (len < 0) {
g_free(buf->data);
buf->data = NULL;
buf->size = 0;
break;
} else if (len == maxlen) {
/*
* We dodn't have space to put the NULL or we have more
* to read. Increase the size and try again
*/
maxlen *= 2;
g_free(buf->data);
buf->data = g_malloc(maxlen);
continue;
}
/*
* Null terminate the readlink output
*/
buf->data[len] = '\0';
buf->size = len;
break;
}
return len;
}
int coroutine_fn v9fs_co_readlink(V9fsPDU *pdu, V9fsPath *path, V9fsString *buf)
{
int err;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
v9fs_path_read_lock(s);
v9fs_co_run_in_worker(
{
err = __readlink(s, path, buf);
if (err < 0) {
err = -errno;
}
});
v9fs_path_unlock(s);
return err;
}
int coroutine_fn v9fs_co_statfs(V9fsPDU *pdu, V9fsPath *path,
struct statfs *stbuf)
{
int err;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
v9fs_path_read_lock(s);
v9fs_co_run_in_worker(
{
err = s->ops->statfs(&s->ctx, path, stbuf);
if (err < 0) {
err = -errno;
}
});
v9fs_path_unlock(s);
return err;
}
int coroutine_fn v9fs_co_chmod(V9fsPDU *pdu, V9fsPath *path, mode_t mode)
{
int err;
FsCred cred;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
cred_init(&cred);
cred.fc_mode = mode;
v9fs_path_read_lock(s);
v9fs_co_run_in_worker(
{
err = s->ops->chmod(&s->ctx, path, &cred);
if (err < 0) {
err = -errno;
}
});
v9fs_path_unlock(s);
return err;
}
int coroutine_fn v9fs_co_utimensat(V9fsPDU *pdu, V9fsPath *path,
struct timespec times[2])
{
int err;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
v9fs_path_read_lock(s);
v9fs_co_run_in_worker(
{
err = s->ops->utimensat(&s->ctx, path, times);
if (err < 0) {
err = -errno;
}
});
v9fs_path_unlock(s);
return err;
}
int coroutine_fn v9fs_co_chown(V9fsPDU *pdu, V9fsPath *path, uid_t uid,
gid_t gid)
{
int err;
FsCred cred;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
cred_init(&cred);
cred.fc_uid = uid;
cred.fc_gid = gid;
v9fs_path_read_lock(s);
v9fs_co_run_in_worker(
{
err = s->ops->chown(&s->ctx, path, &cred);
if (err < 0) {
err = -errno;
}
});
v9fs_path_unlock(s);
return err;
}
int coroutine_fn v9fs_co_truncate(V9fsPDU *pdu, V9fsPath *path, off_t size)
{
int err;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
v9fs_path_read_lock(s);
v9fs_co_run_in_worker(
{
err = s->ops->truncate(&s->ctx, path, size);
if (err < 0) {
err = -errno;
}
});
v9fs_path_unlock(s);
return err;
}
int coroutine_fn v9fs_co_mknod(V9fsPDU *pdu, V9fsFidState *fidp,
V9fsString *name, uid_t uid, gid_t gid,
dev_t dev, mode_t mode, struct stat *stbuf)
{
int err;
V9fsPath path;
FsCred cred;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
cred_init(&cred);
cred.fc_uid = uid;
cred.fc_gid = gid;
cred.fc_mode = mode;
cred.fc_rdev = dev;
v9fs_path_read_lock(s);
v9fs_co_run_in_worker(
{
err = s->ops->mknod(&s->ctx, &fidp->path, name->data, &cred);
if (err < 0) {
err = -errno;
} else {
v9fs_path_init(&path);
err = v9fs_name_to_path(s, &fidp->path, name->data, &path);
if (!err) {
err = s->ops->lstat(&s->ctx, &path, stbuf);
if (err < 0) {
err = -errno;
}
}
v9fs_path_free(&path);
}
});
v9fs_path_unlock(s);
return err;
}
/* Only works with path name based fid */
int coroutine_fn v9fs_co_remove(V9fsPDU *pdu, V9fsPath *path)
{
int err;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
v9fs_path_read_lock(s);
v9fs_co_run_in_worker(
{
err = s->ops->remove(&s->ctx, path->data);
if (err < 0) {
err = -errno;
}
});
v9fs_path_unlock(s);
return err;
}
int coroutine_fn v9fs_co_unlinkat(V9fsPDU *pdu, V9fsPath *path,
V9fsString *name, int flags)
{
int err;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
v9fs_path_read_lock(s);
v9fs_co_run_in_worker(
{
err = s->ops->unlinkat(&s->ctx, path, name->data, flags);
if (err < 0) {
err = -errno;
}
});
v9fs_path_unlock(s);
return err;
}
/* Only work with path name based fid */
int coroutine_fn v9fs_co_rename(V9fsPDU *pdu, V9fsPath *oldpath,
V9fsPath *newpath)
{
int err;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
v9fs_co_run_in_worker(
{
err = s->ops->rename(&s->ctx, oldpath->data, newpath->data);
if (err < 0) {
err = -errno;
}
});
return err;
}
int coroutine_fn v9fs_co_renameat(V9fsPDU *pdu, V9fsPath *olddirpath,
V9fsString *oldname, V9fsPath *newdirpath,
V9fsString *newname)
{
int err;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
v9fs_co_run_in_worker(
{
err = s->ops->renameat(&s->ctx, olddirpath, oldname->data,
newdirpath, newname->data);
if (err < 0) {
err = -errno;
}
});
return err;
}
int coroutine_fn v9fs_co_symlink(V9fsPDU *pdu, V9fsFidState *dfidp,
V9fsString *name, const char *oldpath,
gid_t gid, struct stat *stbuf)
{
int err;
FsCred cred;
V9fsPath path;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
cred_init(&cred);
cred.fc_uid = dfidp->uid;
cred.fc_gid = gid;
cred.fc_mode = 0777;
v9fs_path_read_lock(s);
v9fs_co_run_in_worker(
{
err = s->ops->symlink(&s->ctx, oldpath, &dfidp->path,
name->data, &cred);
if (err < 0) {
err = -errno;
} else {
v9fs_path_init(&path);
err = v9fs_name_to_path(s, &dfidp->path, name->data, &path);
if (!err) {
err = s->ops->lstat(&s->ctx, &path, stbuf);
if (err < 0) {
err = -errno;
}
}
v9fs_path_free(&path);
}
});
v9fs_path_unlock(s);
return err;
}
/*
* For path name based fid we don't block. So we can
* directly call the fs driver ops.
*/
int coroutine_fn v9fs_co_name_to_path(V9fsPDU *pdu, V9fsPath *dirpath,
const char *name, V9fsPath *path)
{
int err;
V9fsState *s = pdu->s;
if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
err = s->ops->name_to_path(&s->ctx, dirpath, name, path);
if (err < 0) {
err = -errno;
}
} else {
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
v9fs_co_run_in_worker(
{
err = s->ops->name_to_path(&s->ctx, dirpath, name, path);
if (err < 0) {
err = -errno;
}
});
}
return err;
}