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daf0b9aca9
Add interfaces to open and create files for proxy file system driver. Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
564 lines
14 KiB
C
564 lines
14 KiB
C
/*
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* Virtio 9p Proxy callback
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*
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* Copyright IBM, Corp. 2011
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*
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* Authors:
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* M. Mohan Kumar <mohan@in.ibm.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*/
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#include <sys/socket.h>
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#include <sys/un.h>
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#include "hw/virtio.h"
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#include "virtio-9p.h"
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#include "fsdev/qemu-fsdev.h"
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#include "virtio-9p-proxy.h"
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typedef struct V9fsProxy {
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int sockfd;
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QemuMutex mutex;
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struct iovec iovec;
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} V9fsProxy;
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/*
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* Return received file descriptor on success in *status.
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* errno is also returned on *status (which will be < 0)
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* return < 0 on transport error.
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*/
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static int v9fs_receivefd(int sockfd, int *status)
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{
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struct iovec iov;
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struct msghdr msg;
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struct cmsghdr *cmsg;
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int retval, data, fd;
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union MsgControl msg_control;
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iov.iov_base = &data;
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iov.iov_len = sizeof(data);
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memset(&msg, 0, sizeof(msg));
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msg.msg_iov = &iov;
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msg.msg_iovlen = 1;
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msg.msg_control = &msg_control;
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msg.msg_controllen = sizeof(msg_control);
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do {
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retval = recvmsg(sockfd, &msg, 0);
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} while (retval < 0 && errno == EINTR);
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if (retval <= 0) {
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return retval;
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}
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/*
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* data is set to V9FS_FD_VALID, if ancillary data is sent. If this
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* request doesn't need ancillary data (fd) or an error occurred,
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* data is set to negative errno value.
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*/
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if (data != V9FS_FD_VALID) {
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*status = data;
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return 0;
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}
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/*
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* File descriptor (fd) is sent in the ancillary data. Check if we
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* indeed received it. One of the reasons to fail to receive it is if
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* we exceeded the maximum number of file descriptors!
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*/
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for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
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if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)) ||
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cmsg->cmsg_level != SOL_SOCKET ||
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cmsg->cmsg_type != SCM_RIGHTS) {
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continue;
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}
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fd = *((int *)CMSG_DATA(cmsg));
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*status = fd;
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return 0;
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}
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*status = -ENFILE; /* Ancillary data sent but not received */
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return 0;
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}
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/*
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* Proxy->header and proxy->request written to socket by QEMU process.
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* This request read by proxy helper process
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* returns 0 on success and -errno on error
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*/
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static int v9fs_request(V9fsProxy *proxy, int type,
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void *response, const char *fmt, ...)
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{
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va_list ap;
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int retval = 0;
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V9fsString *path;
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ProxyHeader header = { 0, 0};
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struct iovec *iovec = NULL;
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int flags, mode, uid, gid;
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qemu_mutex_lock(&proxy->mutex);
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if (proxy->sockfd == -1) {
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retval = -EIO;
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goto err_out;
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}
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iovec = &proxy->iovec;
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va_start(ap, fmt);
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switch (type) {
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case T_OPEN:
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path = va_arg(ap, V9fsString *);
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flags = va_arg(ap, int);
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retval = proxy_marshal(iovec, PROXY_HDR_SZ, "sd", path, flags);
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if (retval > 0) {
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header.size = retval;
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header.type = T_OPEN;
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}
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break;
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case T_CREATE:
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path = va_arg(ap, V9fsString *);
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flags = va_arg(ap, int);
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mode = va_arg(ap, int);
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uid = va_arg(ap, int);
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gid = va_arg(ap, int);
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retval = proxy_marshal(iovec, PROXY_HDR_SZ, "sdddd", path,
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flags, mode, uid, gid);
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if (retval > 0) {
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header.size = retval;
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header.type = T_CREATE;
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}
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break;
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default:
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error_report("Invalid type %d\n", type);
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retval = -EINVAL;
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break;
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}
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va_end(ap);
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if (retval < 0) {
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goto err_out;
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}
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/* marshal the header details */
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proxy_marshal(iovec, 0, "dd", header.type, header.size);
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header.size += PROXY_HDR_SZ;
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retval = qemu_write_full(proxy->sockfd, iovec->iov_base, header.size);
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if (retval != header.size) {
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goto close_error;
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}
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switch (type) {
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case T_OPEN:
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case T_CREATE:
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/*
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* A file descriptor is returned as response for
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* T_OPEN,T_CREATE on success
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*/
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if (v9fs_receivefd(proxy->sockfd, &retval) < 0) {
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goto close_error;
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}
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break;
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}
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err_out:
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qemu_mutex_unlock(&proxy->mutex);
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return retval;
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close_error:
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close(proxy->sockfd);
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proxy->sockfd = -1;
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qemu_mutex_unlock(&proxy->mutex);
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return -EIO;
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}
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static int proxy_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static ssize_t proxy_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
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char *buf, size_t bufsz)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static int proxy_close(FsContext *ctx, V9fsFidOpenState *fs)
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{
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return close(fs->fd);
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}
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static int proxy_closedir(FsContext *ctx, V9fsFidOpenState *fs)
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{
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return closedir(fs->dir);
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}
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static int proxy_open(FsContext *ctx, V9fsPath *fs_path,
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int flags, V9fsFidOpenState *fs)
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{
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fs->fd = v9fs_request(ctx->private, T_OPEN, NULL, "sd", fs_path, flags);
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if (fs->fd < 0) {
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errno = -fs->fd;
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fs->fd = -1;
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}
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return fs->fd;
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}
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static int proxy_opendir(FsContext *ctx,
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V9fsPath *fs_path, V9fsFidOpenState *fs)
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{
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int serrno, fd;
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fs->dir = NULL;
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fd = v9fs_request(ctx->private, T_OPEN, NULL, "sd", fs_path, O_DIRECTORY);
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if (fd < 0) {
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errno = -fd;
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return -1;
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}
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fs->dir = fdopendir(fd);
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if (!fs->dir) {
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serrno = errno;
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close(fd);
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errno = serrno;
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return -1;
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}
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return 0;
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}
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static void proxy_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
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{
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return rewinddir(fs->dir);
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}
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static off_t proxy_telldir(FsContext *ctx, V9fsFidOpenState *fs)
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{
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return telldir(fs->dir);
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}
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static int proxy_readdir_r(FsContext *ctx, V9fsFidOpenState *fs,
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struct dirent *entry,
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struct dirent **result)
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{
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return readdir_r(fs->dir, entry, result);
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}
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static void proxy_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
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{
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return seekdir(fs->dir, off);
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}
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static ssize_t proxy_preadv(FsContext *ctx, V9fsFidOpenState *fs,
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const struct iovec *iov,
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int iovcnt, off_t offset)
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{
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#ifdef CONFIG_PREADV
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return preadv(fs->fd, iov, iovcnt, offset);
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#else
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int err = lseek(fs->fd, offset, SEEK_SET);
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if (err == -1) {
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return err;
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} else {
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return readv(fs->fd, iov, iovcnt);
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}
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#endif
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}
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static ssize_t proxy_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
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const struct iovec *iov,
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int iovcnt, off_t offset)
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{
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ssize_t ret;
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#ifdef CONFIG_PREADV
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ret = pwritev(fs->fd, iov, iovcnt, offset);
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#else
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int err = lseek(fs->fd, offset, SEEK_SET);
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if (err == -1) {
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return err;
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} else {
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ret = writev(fs->fd, iov, iovcnt);
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}
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#endif
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#ifdef CONFIG_SYNC_FILE_RANGE
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if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
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/*
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* Initiate a writeback. This is not a data integrity sync.
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* We want to ensure that we don't leave dirty pages in the cache
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* after write when writeout=immediate is sepcified.
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*/
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sync_file_range(fs->fd, offset, ret,
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SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
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}
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#endif
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return ret;
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}
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static int proxy_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static int proxy_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
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const char *name, FsCred *credp)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static int proxy_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
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const char *name, FsCred *credp)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static int proxy_fstat(FsContext *fs_ctx, int fid_type,
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V9fsFidOpenState *fs, struct stat *stbuf)
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{
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int fd;
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if (fid_type == P9_FID_DIR) {
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fd = dirfd(fs->dir);
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} else {
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fd = fs->fd;
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}
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return fstat(fd, stbuf);
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}
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static int proxy_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
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int flags, FsCred *credp, V9fsFidOpenState *fs)
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{
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V9fsString fullname;
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v9fs_string_init(&fullname);
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v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
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fs->fd = v9fs_request(fs_ctx->private, T_CREATE, NULL, "sdddd",
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&fullname, flags, credp->fc_mode,
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credp->fc_uid, credp->fc_gid);
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v9fs_string_free(&fullname);
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if (fs->fd < 0) {
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errno = -fs->fd;
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fs->fd = -1;
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}
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return fs->fd;
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}
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static int proxy_symlink(FsContext *fs_ctx, const char *oldpath,
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V9fsPath *dir_path, const char *name, FsCred *credp)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static int proxy_link(FsContext *ctx, V9fsPath *oldpath,
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V9fsPath *dirpath, const char *name)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static int proxy_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static int proxy_rename(FsContext *ctx, const char *oldpath,
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const char *newpath)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static int proxy_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static int proxy_utimensat(FsContext *s, V9fsPath *fs_path,
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const struct timespec *buf)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static int proxy_remove(FsContext *ctx, const char *path)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static int proxy_fsync(FsContext *ctx, int fid_type,
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V9fsFidOpenState *fs, int datasync)
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{
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int fd;
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if (fid_type == P9_FID_DIR) {
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fd = dirfd(fs->dir);
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} else {
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fd = fs->fd;
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}
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if (datasync) {
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return qemu_fdatasync(fd);
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} else {
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return fsync(fd);
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}
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}
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static int proxy_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static ssize_t proxy_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
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const char *name, void *value, size_t size)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static ssize_t proxy_llistxattr(FsContext *ctx, V9fsPath *fs_path,
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void *value, size_t size)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static int proxy_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
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void *value, size_t size, int flags)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static int proxy_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
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const char *name)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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static int proxy_name_to_path(FsContext *ctx, V9fsPath *dir_path,
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const char *name, V9fsPath *target)
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{
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if (dir_path) {
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v9fs_string_sprintf((V9fsString *)target, "%s/%s",
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dir_path->data, name);
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} else {
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v9fs_string_sprintf((V9fsString *)target, "%s", name);
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}
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/* Bump the size for including terminating NULL */
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target->size++;
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return 0;
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}
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static int proxy_renameat(FsContext *ctx, V9fsPath *olddir,
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const char *old_name, V9fsPath *newdir,
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const char *new_name)
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{
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int ret;
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V9fsString old_full_name, new_full_name;
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v9fs_string_init(&old_full_name);
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v9fs_string_init(&new_full_name);
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v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name);
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v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name);
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ret = proxy_rename(ctx, old_full_name.data, new_full_name.data);
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v9fs_string_free(&old_full_name);
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v9fs_string_free(&new_full_name);
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return ret;
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}
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static int proxy_unlinkat(FsContext *ctx, V9fsPath *dir,
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const char *name, int flags)
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{
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int ret;
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V9fsString fullname;
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v9fs_string_init(&fullname);
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v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name);
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ret = proxy_remove(ctx, fullname.data);
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v9fs_string_free(&fullname);
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return ret;
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}
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static int proxy_parse_opts(QemuOpts *opts, struct FsDriverEntry *fs)
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{
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const char *sock_fd = qemu_opt_get(opts, "sock_fd");
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if (sock_fd) {
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fprintf(stderr, "sock_fd option not specified\n");
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return -1;
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}
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fs->path = g_strdup(sock_fd);
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return 0;
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}
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static int proxy_init(FsContext *ctx)
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{
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V9fsProxy *proxy = g_malloc(sizeof(V9fsProxy));
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int sock_id;
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sock_id = atoi(ctx->fs_root);
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if (sock_id < 0) {
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fprintf(stderr, "socket descriptor not initialized\n");
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return -1;
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}
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g_free(ctx->fs_root);
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proxy->iovec.iov_base = g_malloc(PROXY_MAX_IO_SZ + PROXY_HDR_SZ);
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proxy->iovec.iov_len = PROXY_MAX_IO_SZ + PROXY_HDR_SZ;
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ctx->private = proxy;
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proxy->sockfd = sock_id;
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qemu_mutex_init(&proxy->mutex);
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ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
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return 0;
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}
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FileOperations proxy_ops = {
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.parse_opts = proxy_parse_opts,
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.init = proxy_init,
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.lstat = proxy_lstat,
|
|
.readlink = proxy_readlink,
|
|
.close = proxy_close,
|
|
.closedir = proxy_closedir,
|
|
.open = proxy_open,
|
|
.opendir = proxy_opendir,
|
|
.rewinddir = proxy_rewinddir,
|
|
.telldir = proxy_telldir,
|
|
.readdir_r = proxy_readdir_r,
|
|
.seekdir = proxy_seekdir,
|
|
.preadv = proxy_preadv,
|
|
.pwritev = proxy_pwritev,
|
|
.chmod = proxy_chmod,
|
|
.mknod = proxy_mknod,
|
|
.mkdir = proxy_mkdir,
|
|
.fstat = proxy_fstat,
|
|
.open2 = proxy_open2,
|
|
.symlink = proxy_symlink,
|
|
.link = proxy_link,
|
|
.truncate = proxy_truncate,
|
|
.rename = proxy_rename,
|
|
.chown = proxy_chown,
|
|
.utimensat = proxy_utimensat,
|
|
.remove = proxy_remove,
|
|
.fsync = proxy_fsync,
|
|
.statfs = proxy_statfs,
|
|
.lgetxattr = proxy_lgetxattr,
|
|
.llistxattr = proxy_llistxattr,
|
|
.lsetxattr = proxy_lsetxattr,
|
|
.lremovexattr = proxy_lremovexattr,
|
|
.name_to_path = proxy_name_to_path,
|
|
.renameat = proxy_renameat,
|
|
.unlinkat = proxy_unlinkat,
|
|
};
|