xemu/hw/9pfs/codir.c
Aneesh Kumar K.V 02cb7f3a25 hw/9pfs: Use read-write lock for protecting fid path.
On rename we take the write lock and this ensure path
doesn't change as we operate on them.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2011-09-22 21:38:52 +05:30

139 lines
3.1 KiB
C

/*
* Virtio 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 "fsdev/qemu-fsdev.h"
#include "qemu-thread.h"
#include "qemu-coroutine.h"
#include "virtio-9p-coth.h"
int v9fs_co_readdir_r(V9fsState *s, V9fsFidState *fidp, struct dirent *dent,
struct dirent **result)
{
int err;
v9fs_co_run_in_worker(
{
errno = 0;
err = s->ops->readdir_r(&s->ctx, fidp->fs.dir, dent, result);
if (!*result && errno) {
err = -errno;
} else {
err = 0;
}
});
return err;
}
off_t v9fs_co_telldir(V9fsState *s, V9fsFidState *fidp)
{
off_t err;
v9fs_co_run_in_worker(
{
err = s->ops->telldir(&s->ctx, fidp->fs.dir);
if (err < 0) {
err = -errno;
}
});
return err;
}
void v9fs_co_seekdir(V9fsState *s, V9fsFidState *fidp, off_t offset)
{
v9fs_co_run_in_worker(
{
s->ops->seekdir(&s->ctx, fidp->fs.dir, offset);
});
}
void v9fs_co_rewinddir(V9fsState *s, V9fsFidState *fidp)
{
v9fs_co_run_in_worker(
{
s->ops->rewinddir(&s->ctx, fidp->fs.dir);
});
}
int v9fs_co_mkdir(V9fsState *s, V9fsFidState *fidp, V9fsString *name,
mode_t mode, uid_t uid, gid_t gid, struct stat *stbuf)
{
int err;
FsCred cred;
V9fsString fullname;
cred_init(&cred);
cred.fc_mode = mode;
cred.fc_uid = uid;
cred.fc_gid = gid;
v9fs_string_init(&fullname);
qemu_co_rwlock_rdlock(&s->rename_lock);
v9fs_string_sprintf(&fullname, "%s/%s", fidp->path.data, name->data);
v9fs_co_run_in_worker(
{
err = s->ops->mkdir(&s->ctx, fullname.data, &cred);
if (err < 0) {
err = -errno;
} else {
err = s->ops->lstat(&s->ctx, fullname.data, stbuf);
if (err < 0) {
err = -errno;
}
}
});
qemu_co_rwlock_unlock(&s->rename_lock);
v9fs_string_free(&fullname);
return err;
}
int v9fs_co_opendir(V9fsState *s, V9fsFidState *fidp)
{
int err;
qemu_co_rwlock_rdlock(&s->rename_lock);
v9fs_co_run_in_worker(
{
fidp->fs.dir = s->ops->opendir(&s->ctx, fidp->path.data);
if (!fidp->fs.dir) {
err = -errno;
} else {
err = 0;
}
});
qemu_co_rwlock_unlock(&s->rename_lock);
if (!err) {
total_open_fd++;
if (total_open_fd > open_fd_hw) {
v9fs_reclaim_fd(s);
}
}
return err;
}
int v9fs_co_closedir(V9fsState *s, DIR *dir)
{
int err;
v9fs_co_run_in_worker(
{
err = s->ops->closedir(&s->ctx, dir);
if (err < 0) {
err = -errno;
}
});
if (!err) {
total_open_fd--;
}
return err;
}