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