blob: 71174c3e4abddb2a83192629614128395330080f [file] [log] [blame]
/*
* 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.
*
*/
/*
* Not so fast! You might want to read the 9p developer docs first:
* https://wiki.qemu.org/Documentation/9p
*/
#include "qemu/osdep.h"
#include "fsdev/qemu-fsdev.h"
#include "qemu/thread.h"
#include "qemu/main-loop.h"
#include "coth.h"
int coroutine_fn v9fs_co_st_gen(V9fsPDU *pdu, V9fsPath *path, mode_t st_mode,
V9fsStatDotl *v9stat)
{
int err = 0;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
if (s->ctx.exops.get_st_gen) {
v9fs_path_read_lock(s);
v9fs_co_run_in_worker(
{
err = s->ctx.exops.get_st_gen(&s->ctx, path, st_mode,
&v9stat->st_gen);
if (err < 0) {
err = -errno;
}
});
v9fs_path_unlock(s);
}
return err;
}
int coroutine_fn v9fs_co_lstat(V9fsPDU *pdu, V9fsPath *path, struct stat *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->lstat(&s->ctx, path, stbuf);
if (err < 0) {
err = -errno;
}
});
v9fs_path_unlock(s);
return err;
}
int coroutine_fn v9fs_co_fstat(V9fsPDU *pdu, V9fsFidState *fidp,
struct stat *stbuf)
{
int err;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
v9fs_co_run_in_worker(
{
err = s->ops->fstat(&s->ctx, fidp->fid_type, &fidp->fs, stbuf);
if (err < 0) {
err = -errno;
}
});
/*
* Some FS driver (local:mapped-file) can't support fetching attributes
* using file descriptor. Use Path name in that case.
*/
if (err == -EOPNOTSUPP) {
err = v9fs_co_lstat(pdu, &fidp->path, stbuf);
if (err == -ENOENT) {
/*
* fstat on an unlinked file. Work with partial results
* returned from s->ops->fstat
*/
err = 0;
}
}
return err;
}
int coroutine_fn v9fs_co_open(V9fsPDU *pdu, V9fsFidState *fidp, 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->open(&s->ctx, &fidp->path, flags, &fidp->fs);
if (err == -1) {
err = -errno;
} else {
err = 0;
}
});
v9fs_path_unlock(s);
if (!err) {
total_open_fd++;
if (total_open_fd > open_fd_hw) {
v9fs_reclaim_fd(pdu);
}
}
return err;
}
int coroutine_fn v9fs_co_open2(V9fsPDU *pdu, V9fsFidState *fidp,
V9fsString *name, gid_t gid, int flags, int mode,
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_mode = mode & 07777;
cred.fc_uid = fidp->uid;
cred.fc_gid = gid;
/*
* Hold the directory fid lock so that directory path name
* don't change. Take the write lock to be sure this fid
* cannot be used by another operation.
*/
v9fs_path_write_lock(s);
v9fs_co_run_in_worker(
{
err = s->ops->open2(&s->ctx, &fidp->path,
name->data, flags, &cred, &fidp->fs);
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;
s->ops->close(&s->ctx, &fidp->fs);
} else {
v9fs_path_copy(&fidp->path, &path);
}
} else {
s->ops->close(&s->ctx, &fidp->fs);
}
v9fs_path_free(&path);
}
});
v9fs_path_unlock(s);
if (!err) {
total_open_fd++;
if (total_open_fd > open_fd_hw) {
v9fs_reclaim_fd(pdu);
}
}
return err;
}
int coroutine_fn v9fs_co_close(V9fsPDU *pdu, V9fsFidOpenState *fs)
{
int err;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
v9fs_co_run_in_worker(
{
err = s->ops->close(&s->ctx, fs);
if (err < 0) {
err = -errno;
}
});
if (!err) {
total_open_fd--;
}
return err;
}
int coroutine_fn v9fs_co_fsync(V9fsPDU *pdu, V9fsFidState *fidp, int datasync)
{
int err;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
v9fs_co_run_in_worker(
{
err = s->ops->fsync(&s->ctx, fidp->fid_type, &fidp->fs, datasync);
if (err < 0) {
err = -errno;
}
});
return err;
}
int coroutine_fn v9fs_co_link(V9fsPDU *pdu, V9fsFidState *oldfid,
V9fsFidState *newdirfid, V9fsString *name)
{
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->link(&s->ctx, &oldfid->path,
&newdirfid->path, name->data);
if (err < 0) {
err = -errno;
}
});
v9fs_path_unlock(s);
return err;
}
int coroutine_fn v9fs_co_pwritev(V9fsPDU *pdu, V9fsFidState *fidp,
struct iovec *iov, int iovcnt, int64_t offset)
{
int err;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
fsdev_co_throttle_request(s->ctx.fst, THROTTLE_WRITE, iov, iovcnt);
v9fs_co_run_in_worker(
{
err = s->ops->pwritev(&s->ctx, &fidp->fs, iov, iovcnt, offset);
if (err < 0) {
err = -errno;
}
});
return err;
}
int coroutine_fn v9fs_co_preadv(V9fsPDU *pdu, V9fsFidState *fidp,
struct iovec *iov, int iovcnt, int64_t offset)
{
int err;
V9fsState *s = pdu->s;
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
fsdev_co_throttle_request(s->ctx.fst, THROTTLE_READ, iov, iovcnt);
v9fs_co_run_in_worker(
{
err = s->ops->preadv(&s->ctx, &fidp->fs, iov, iovcnt, offset);
if (err < 0) {
err = -errno;
}
});
return err;
}