612 lines
15 KiB
C
612 lines
15 KiB
C
/*
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* Virtio 9p handle 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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* Aneesh Kumar K.V <aneesh.kumar@linux.vnet.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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*/
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#include "hw/virtio.h"
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#include "virtio-9p.h"
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#include "virtio-9p-xattr.h"
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#include <arpa/inet.h>
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#include <pwd.h>
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#include <grp.h>
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#include <sys/socket.h>
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#include <sys/un.h>
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#include <attr/xattr.h>
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#include <unistd.h>
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struct handle_data {
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int mountfd;
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int handle_bytes;
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};
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#if __GLIBC__ <= 2 && __GLIBC_MINOR__ < 14
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struct file_handle {
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unsigned int handle_bytes;
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int handle_type;
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unsigned char handle[0];
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};
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#endif
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#ifndef AT_EMPTY_PATH
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#define AT_EMPTY_PATH 0x1000 /* Allow empty relative pathname */
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#endif
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#ifndef O_PATH
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#define O_PATH 010000000
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#endif
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#ifndef __NR_name_to_handle_at
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#if defined(__i386__)
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#define __NR_name_to_handle_at 341
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#define __NR_open_by_handle_at 342
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#elif defined(__x86_64__)
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#define __NR_name_to_handle_at 303
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#define __NR_open_by_handle_at 304
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#endif
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#endif
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#ifdef __NR_name_to_handle_at
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static inline int name_to_handle(int dirfd, const char *name,
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struct file_handle *fh, int *mnt_id, int flags)
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{
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return syscall(__NR_name_to_handle_at, dirfd, name, fh, mnt_id, flags);
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}
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static inline int open_by_handle(int mountfd, const char *fh, int flags)
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{
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return syscall(__NR_open_by_handle_at, mountfd, fh, flags);
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}
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#else
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static inline int name_to_handle(int dirfd, const char *name,
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struct file_handle *fh, int *mnt_id, int flags)
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{
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errno = ENOSYS;
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return -1;
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}
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static inline int open_by_handle(int mountfd, const char *fh, int flags)
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{
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errno = ENOSYS;
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return -1;
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}
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#endif
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static int handle_update_file_cred(int dirfd, const char *name, FsCred *credp)
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{
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int fd, ret;
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fd = openat(dirfd, name, O_NONBLOCK | O_NOFOLLOW);;
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if (fd < 0) {
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return fd;
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}
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ret = fchmod(fd, credp->fc_mode & 07777);
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if (ret < 0) {
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goto err_out;
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}
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ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
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err_out:
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close(fd);
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return ret;
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}
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static int handle_lstat(FsContext *fs_ctx, V9fsPath *fs_path,
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struct stat *stbuf)
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{
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int fd, ret;
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struct handle_data *data = (struct handle_data *)fs_ctx->private;
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fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
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if (fd < 0) {
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return fd;
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}
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ret = fstatat(fd, "", stbuf, AT_EMPTY_PATH);
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close(fd);
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return ret;
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}
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static ssize_t handle_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
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char *buf, size_t bufsz)
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{
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int fd, ret;
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struct handle_data *data = (struct handle_data *)fs_ctx->private;
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fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
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if (fd < 0) {
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return fd;
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}
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ret = readlinkat(fd, "", buf, bufsz);
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close(fd);
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return ret;
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}
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static int handle_close(FsContext *ctx, int fd)
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{
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return close(fd);
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}
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static int handle_closedir(FsContext *ctx, DIR *dir)
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{
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return closedir(dir);
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}
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static int handle_open(FsContext *ctx, V9fsPath *fs_path, int flags)
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{
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struct handle_data *data = (struct handle_data *)ctx->private;
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return open_by_handle(data->mountfd, fs_path->data, flags);
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}
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static DIR *handle_opendir(FsContext *ctx, V9fsPath *fs_path)
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{
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int fd;
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fd = handle_open(ctx, fs_path, O_DIRECTORY);
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if (fd < 0) {
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return NULL;
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}
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return fdopendir(fd);
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}
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static void handle_rewinddir(FsContext *ctx, DIR *dir)
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{
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return rewinddir(dir);
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}
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static off_t handle_telldir(FsContext *ctx, DIR *dir)
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{
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return telldir(dir);
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}
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static int handle_readdir_r(FsContext *ctx, DIR *dir, struct dirent *entry,
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struct dirent **result)
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{
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return readdir_r(dir, entry, result);
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}
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static void handle_seekdir(FsContext *ctx, DIR *dir, off_t off)
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{
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return seekdir(dir, off);
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}
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static ssize_t handle_preadv(FsContext *ctx, int fd, 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(fd, iov, iovcnt, offset);
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#else
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int err = lseek(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(fd, iov, iovcnt);
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}
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#endif
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}
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static ssize_t handle_pwritev(FsContext *ctx, int fd, 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 pwritev(fd, iov, iovcnt, offset);
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#else
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int err = lseek(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 writev(fd, iov, iovcnt);
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}
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#endif
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}
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static int handle_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
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{
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int fd, ret;
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struct handle_data *data = (struct handle_data *)fs_ctx->private;
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fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
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if (fd < 0) {
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return fd;
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}
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ret = fchmod(fd, credp->fc_mode);
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close(fd);
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return ret;
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}
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static int handle_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
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const char *name, FsCred *credp)
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{
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int dirfd, ret;
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struct handle_data *data = (struct handle_data *)fs_ctx->private;
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dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
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if (dirfd < 0) {
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return dirfd;
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}
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ret = mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev);
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if (!ret) {
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ret = handle_update_file_cred(dirfd, name, credp);
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}
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close(dirfd);
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return ret;
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}
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static int handle_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
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const char *name, FsCred *credp)
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{
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int dirfd, ret;
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struct handle_data *data = (struct handle_data *)fs_ctx->private;
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dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
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if (dirfd < 0) {
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return dirfd;
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}
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ret = mkdirat(dirfd, name, credp->fc_mode);
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if (!ret) {
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ret = handle_update_file_cred(dirfd, name, credp);
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}
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close(dirfd);
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return ret;
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}
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static int handle_fstat(FsContext *fs_ctx, int fd, struct stat *stbuf)
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{
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return fstat(fd, stbuf);
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}
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static int handle_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
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int flags, FsCred *credp)
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{
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int ret;
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int dirfd, fd;
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struct handle_data *data = (struct handle_data *)fs_ctx->private;
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dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
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if (dirfd < 0) {
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return dirfd;
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}
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fd = openat(dirfd, name, flags | O_NOFOLLOW, credp->fc_mode);
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if (fd >= 0) {
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ret = handle_update_file_cred(dirfd, name, credp);
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if (ret < 0) {
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close(fd);
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fd = ret;
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}
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}
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close(dirfd);
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return fd;
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}
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static int handle_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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int fd, dirfd, ret;
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struct handle_data *data = (struct handle_data *)fs_ctx->private;
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dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
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if (dirfd < 0) {
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return dirfd;
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}
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ret = symlinkat(oldpath, dirfd, name);
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if (!ret) {
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fd = openat(dirfd, name, O_PATH | O_NOFOLLOW);
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if (fd < 0) {
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ret = fd;
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goto err_out;
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}
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ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
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close(fd);
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}
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err_out:
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close(dirfd);
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return ret;
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}
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static int handle_link(FsContext *ctx, V9fsPath *oldpath,
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V9fsPath *dirpath, const char *name)
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{
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int oldfd, newdirfd, ret;
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struct handle_data *data = (struct handle_data *)ctx->private;
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oldfd = open_by_handle(data->mountfd, oldpath->data, O_PATH);
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if (oldfd < 0) {
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return oldfd;
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}
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newdirfd = open_by_handle(data->mountfd, dirpath->data, O_PATH);
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if (newdirfd < 0) {
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close(oldfd);
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return newdirfd;
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}
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ret = linkat(oldfd, "", newdirfd, name, AT_EMPTY_PATH);
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close(newdirfd);
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close(oldfd);
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return ret;
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}
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static int handle_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
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{
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int fd, ret;
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struct handle_data *data = (struct handle_data *)ctx->private;
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fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK | O_WRONLY);
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if (fd < 0) {
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return fd;
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}
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ret = ftruncate(fd, size);
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close(fd);
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return ret;
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}
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static int handle_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 handle_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
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{
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int fd, ret;
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struct handle_data *data = (struct handle_data *)fs_ctx->private;
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fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
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if (fd < 0) {
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return fd;
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}
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ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
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close(fd);
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return ret;
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}
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static int handle_utimensat(FsContext *ctx, V9fsPath *fs_path,
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const struct timespec *buf)
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{
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int fd, ret;
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struct handle_data *data = (struct handle_data *)ctx->private;
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fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
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if (fd < 0) {
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return fd;
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}
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ret = futimens(fd, buf);
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close(fd);
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return ret;
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}
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static int handle_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 handle_fsync(FsContext *ctx, int fd, int datasync)
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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 handle_statfs(FsContext *ctx, V9fsPath *fs_path,
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struct statfs *stbuf)
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{
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int fd, ret;
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struct handle_data *data = (struct handle_data *)ctx->private;
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fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
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if (fd < 0) {
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return fd;
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}
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ret = fstatfs(fd, stbuf);
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close(fd);
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return ret;
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}
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static ssize_t handle_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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int fd, ret;
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struct handle_data *data = (struct handle_data *)ctx->private;
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fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
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if (fd < 0) {
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return fd;
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}
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ret = fgetxattr(fd, name, value, size);
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close(fd);
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return ret;
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}
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static ssize_t handle_llistxattr(FsContext *ctx, V9fsPath *fs_path,
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void *value, size_t size)
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{
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int fd, ret;
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struct handle_data *data = (struct handle_data *)ctx->private;
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fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
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if (fd < 0) {
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return fd;
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}
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ret = flistxattr(fd, value, size);
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close(fd);
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return ret;
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}
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static int handle_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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int fd, ret;
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struct handle_data *data = (struct handle_data *)ctx->private;
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fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
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if (fd < 0) {
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return fd;
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}
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ret = fsetxattr(fd, name, value, size, flags);
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close(fd);
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return ret;
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}
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static int handle_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
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const char *name)
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{
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int fd, ret;
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struct handle_data *data = (struct handle_data *)ctx->private;
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fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
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if (fd < 0) {
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return fd;
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}
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ret = fremovexattr(fd, name);
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close(fd);
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return ret;
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}
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static int handle_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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char buffer[PATH_MAX];
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struct file_handle *fh;
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int dirfd, ret, mnt_id;
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struct handle_data *data = (struct handle_data *)ctx->private;
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/* "." and ".." are not allowed */
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if (!strcmp(name, ".") || !strcmp(name, "..")) {
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errno = EINVAL;
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return -1;
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}
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if (dir_path) {
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dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
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} else {
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/* relative to export root */
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dirfd = open(rpath(ctx, ".", buffer), O_DIRECTORY);
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}
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if (dirfd < 0) {
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return dirfd;
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}
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fh = g_malloc(sizeof(struct file_handle) + data->handle_bytes);
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fh->handle_bytes = data->handle_bytes;
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/* add a "./" at the begining of the path */
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snprintf(buffer, PATH_MAX, "./%s", name);
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/* flag = 0 imply don't follow symlink */
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ret = name_to_handle(dirfd, buffer, fh, &mnt_id, 0);
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if (!ret) {
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target->data = (char *)fh;
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target->size = sizeof(struct file_handle) + data->handle_bytes;
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} else {
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g_free(fh);
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}
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close(dirfd);
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return ret;
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}
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static int handle_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 olddirfd, newdirfd, ret;
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struct handle_data *data = (struct handle_data *)ctx->private;
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olddirfd = open_by_handle(data->mountfd, olddir->data, O_PATH);
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if (olddirfd < 0) {
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return olddirfd;
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}
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newdirfd = open_by_handle(data->mountfd, newdir->data, O_PATH);
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if (newdirfd < 0) {
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close(olddirfd);
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return newdirfd;
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}
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ret = renameat(olddirfd, old_name, newdirfd, new_name);
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close(newdirfd);
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close(olddirfd);
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return ret;
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}
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|
|
static int handle_unlinkat(FsContext *ctx, V9fsPath *dir,
|
|
const char *name, int flags)
|
|
{
|
|
int dirfd, ret;
|
|
struct handle_data *data = (struct handle_data *)ctx->private;
|
|
|
|
dirfd = open_by_handle(data->mountfd, dir->data, O_PATH);
|
|
if (dirfd < 0) {
|
|
return dirfd;
|
|
}
|
|
|
|
ret = unlinkat(dirfd, name, flags);
|
|
close(dirfd);
|
|
return ret;
|
|
}
|
|
|
|
static int handle_init(FsContext *ctx)
|
|
{
|
|
int ret, mnt_id;
|
|
struct file_handle fh;
|
|
struct handle_data *data = g_malloc(sizeof(struct handle_data));
|
|
data->mountfd = open(ctx->fs_root, O_DIRECTORY);
|
|
if (data->mountfd < 0) {
|
|
ret = data->mountfd;
|
|
goto err_out;
|
|
}
|
|
memset(&fh, 0, sizeof(struct file_handle));
|
|
ret = name_to_handle(data->mountfd, ".", &fh, &mnt_id, 0);
|
|
if (ret && errno == EOVERFLOW) {
|
|
data->handle_bytes = fh.handle_bytes;
|
|
ctx->private = data;
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
/* we got 0 byte handle ? */
|
|
ret = -1;
|
|
close(data->mountfd);
|
|
err_out:
|
|
g_free(data);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
FileOperations handle_ops = {
|
|
.init = handle_init,
|
|
.lstat = handle_lstat,
|
|
.readlink = handle_readlink,
|
|
.close = handle_close,
|
|
.closedir = handle_closedir,
|
|
.open = handle_open,
|
|
.opendir = handle_opendir,
|
|
.rewinddir = handle_rewinddir,
|
|
.telldir = handle_telldir,
|
|
.readdir_r = handle_readdir_r,
|
|
.seekdir = handle_seekdir,
|
|
.preadv = handle_preadv,
|
|
.pwritev = handle_pwritev,
|
|
.chmod = handle_chmod,
|
|
.mknod = handle_mknod,
|
|
.mkdir = handle_mkdir,
|
|
.fstat = handle_fstat,
|
|
.open2 = handle_open2,
|
|
.symlink = handle_symlink,
|
|
.link = handle_link,
|
|
.truncate = handle_truncate,
|
|
.rename = handle_rename,
|
|
.chown = handle_chown,
|
|
.utimensat = handle_utimensat,
|
|
.remove = handle_remove,
|
|
.fsync = handle_fsync,
|
|
.statfs = handle_statfs,
|
|
.lgetxattr = handle_lgetxattr,
|
|
.llistxattr = handle_llistxattr,
|
|
.lsetxattr = handle_lsetxattr,
|
|
.lremovexattr = handle_lremovexattr,
|
|
.name_to_path = handle_name_to_path,
|
|
.renameat = handle_renameat,
|
|
.unlinkat = handle_unlinkat,
|
|
};
|