572 lines
15 KiB
C
572 lines
15 KiB
C
/*
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* Virtio 9p synthetic file system support
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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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* Malahal Naineni <malahal@us.ibm.com>
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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 "fsdev/qemu-fsdev.h"
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#include "virtio-9p-synth.h"
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#include <sys/stat.h>
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/* Root node for synth file system */
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V9fsSynthNode v9fs_synth_root = {
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.name = "/",
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.actual_attr = {
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.mode = 0555 | S_IFDIR,
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.nlink = 1,
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},
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.attr = &v9fs_synth_root.actual_attr,
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};
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static QemuMutex v9fs_synth_mutex;
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static int v9fs_synth_node_count;
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/* set to 1 when the synth fs is ready */
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static int v9fs_synth_fs;
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static V9fsSynthNode *v9fs_add_dir_node(V9fsSynthNode *parent, int mode,
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const char *name,
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V9fsSynthNodeAttr *attr, int inode)
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{
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V9fsSynthNode *node;
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/* Add directory type and remove write bits */
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mode = ((mode & 0777) | S_IFDIR) & ~(S_IWUSR | S_IWGRP | S_IWOTH);
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node = g_malloc0(sizeof(V9fsSynthNode));
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if (attr) {
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/* We are adding .. or . entries */
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node->attr = attr;
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node->attr->nlink++;
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} else {
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node->attr = &node->actual_attr;
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node->attr->inode = inode;
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node->attr->nlink = 1;
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/* We don't allow write to directories */
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node->attr->mode = mode;
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node->attr->write = NULL;
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node->attr->read = NULL;
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}
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node->private = node;
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strncpy(node->name, name, sizeof(node->name));
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QLIST_INSERT_HEAD_RCU(&parent->child, node, sibling);
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return node;
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}
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int qemu_v9fs_synth_mkdir(V9fsSynthNode *parent, int mode,
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const char *name, V9fsSynthNode **result)
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{
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int ret;
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V9fsSynthNode *node, *tmp;
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if (!v9fs_synth_fs) {
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return EAGAIN;
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}
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if (!name || (strlen(name) >= NAME_MAX)) {
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return EINVAL;
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}
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if (!parent) {
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parent = &v9fs_synth_root;
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}
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qemu_mutex_lock(&v9fs_synth_mutex);
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QLIST_FOREACH(tmp, &parent->child, sibling) {
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if (!strcmp(tmp->name, name)) {
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ret = EEXIST;
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goto err_out;
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}
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}
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/* Add the name */
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node = v9fs_add_dir_node(parent, mode, name, NULL, v9fs_synth_node_count++);
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v9fs_add_dir_node(node, parent->attr->mode, "..",
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parent->attr, parent->attr->inode);
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v9fs_add_dir_node(node, node->attr->mode, ".",
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node->attr, node->attr->inode);
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*result = node;
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ret = 0;
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err_out:
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qemu_mutex_unlock(&v9fs_synth_mutex);
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return ret;
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}
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int qemu_v9fs_synth_add_file(V9fsSynthNode *parent, int mode,
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const char *name, v9fs_synth_read read,
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v9fs_synth_write write, void *arg)
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{
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int ret;
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V9fsSynthNode *node, *tmp;
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if (!v9fs_synth_fs) {
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return EAGAIN;
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}
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if (!name || (strlen(name) >= NAME_MAX)) {
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return EINVAL;
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}
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if (!parent) {
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parent = &v9fs_synth_root;
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}
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qemu_mutex_lock(&v9fs_synth_mutex);
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QLIST_FOREACH(tmp, &parent->child, sibling) {
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if (!strcmp(tmp->name, name)) {
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ret = EEXIST;
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goto err_out;
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}
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}
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/* Add file type and remove write bits */
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mode = ((mode & 0777) | S_IFREG);
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node = g_malloc0(sizeof(V9fsSynthNode));
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node->attr = &node->actual_attr;
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node->attr->inode = v9fs_synth_node_count++;
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node->attr->nlink = 1;
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node->attr->read = read;
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node->attr->write = write;
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node->attr->mode = mode;
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node->private = arg;
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strncpy(node->name, name, sizeof(node->name));
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QLIST_INSERT_HEAD_RCU(&parent->child, node, sibling);
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ret = 0;
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err_out:
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qemu_mutex_unlock(&v9fs_synth_mutex);
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return ret;
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}
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static void v9fs_synth_fill_statbuf(V9fsSynthNode *node, struct stat *stbuf)
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{
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stbuf->st_dev = 0;
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stbuf->st_ino = node->attr->inode;
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stbuf->st_mode = node->attr->mode;
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stbuf->st_nlink = node->attr->nlink;
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stbuf->st_uid = 0;
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stbuf->st_gid = 0;
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stbuf->st_rdev = 0;
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stbuf->st_size = 0;
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stbuf->st_blksize = 0;
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stbuf->st_blocks = 0;
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stbuf->st_atime = 0;
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stbuf->st_mtime = 0;
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stbuf->st_ctime = 0;
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}
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static int v9fs_synth_lstat(FsContext *fs_ctx,
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V9fsPath *fs_path, struct stat *stbuf)
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{
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V9fsSynthNode *node = *(V9fsSynthNode **)fs_path->data;
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v9fs_synth_fill_statbuf(node, stbuf);
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return 0;
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}
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static int v9fs_synth_fstat(FsContext *fs_ctx,
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V9fsFidOpenState *fs, struct stat *stbuf)
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{
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V9fsSynthOpenState *synth_open = fs->private;
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v9fs_synth_fill_statbuf(synth_open->node, stbuf);
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return 0;
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}
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static int v9fs_synth_opendir(FsContext *ctx,
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V9fsPath *fs_path, V9fsFidOpenState *fs)
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{
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V9fsSynthOpenState *synth_open;
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V9fsSynthNode *node = *(V9fsSynthNode **)fs_path->data;
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synth_open = g_malloc(sizeof(*synth_open));
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synth_open->node = node;
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node->open_count++;
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fs->private = synth_open;
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return 0;
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}
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static int v9fs_synth_closedir(FsContext *ctx, V9fsFidOpenState *fs)
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{
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V9fsSynthOpenState *synth_open = fs->private;
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V9fsSynthNode *node = synth_open->node;
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node->open_count--;
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g_free(synth_open);
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fs->private = NULL;
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return 0;
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}
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static off_t v9fs_synth_telldir(FsContext *ctx, V9fsFidOpenState *fs)
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{
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V9fsSynthOpenState *synth_open = fs->private;
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return synth_open->offset;
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}
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static void v9fs_synth_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
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{
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V9fsSynthOpenState *synth_open = fs->private;
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synth_open->offset = off;
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}
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static void v9fs_synth_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
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{
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v9fs_synth_seekdir(ctx, fs, 0);
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}
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static void v9fs_synth_direntry(V9fsSynthNode *node,
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struct dirent *entry, off_t off)
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{
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strcpy(entry->d_name, node->name);
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entry->d_ino = node->attr->inode;
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entry->d_off = off + 1;
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}
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static int v9fs_synth_get_dentry(V9fsSynthNode *dir, struct dirent *entry,
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struct dirent **result, off_t off)
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{
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int i = 0;
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V9fsSynthNode *node;
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rcu_read_lock();
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QLIST_FOREACH(node, &dir->child, sibling) {
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/* This is the off child of the directory */
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if (i == off) {
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break;
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}
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i++;
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}
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rcu_read_unlock();
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if (!node) {
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/* end of directory */
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*result = NULL;
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return 0;
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}
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v9fs_synth_direntry(node, entry, off);
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*result = entry;
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return 0;
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}
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static int v9fs_synth_readdir_r(FsContext *ctx, V9fsFidOpenState *fs,
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struct dirent *entry, struct dirent **result)
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{
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int ret;
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V9fsSynthOpenState *synth_open = fs->private;
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V9fsSynthNode *node = synth_open->node;
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ret = v9fs_synth_get_dentry(node, entry, result, synth_open->offset);
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if (!ret && *result != NULL) {
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synth_open->offset++;
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}
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return ret;
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}
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static int v9fs_synth_open(FsContext *ctx, V9fsPath *fs_path,
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int flags, V9fsFidOpenState *fs)
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{
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V9fsSynthOpenState *synth_open;
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V9fsSynthNode *node = *(V9fsSynthNode **)fs_path->data;
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synth_open = g_malloc(sizeof(*synth_open));
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synth_open->node = node;
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node->open_count++;
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fs->private = synth_open;
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return 0;
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}
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static int v9fs_synth_open2(FsContext *fs_ctx, V9fsPath *dir_path,
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const char *name, int flags,
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FsCred *credp, V9fsFidOpenState *fs)
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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 int v9fs_synth_close(FsContext *ctx, V9fsFidOpenState *fs)
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{
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V9fsSynthOpenState *synth_open = fs->private;
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V9fsSynthNode *node = synth_open->node;
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node->open_count--;
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g_free(synth_open);
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fs->private = NULL;
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return 0;
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}
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static ssize_t v9fs_synth_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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int i, count = 0, wcount;
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V9fsSynthOpenState *synth_open = fs->private;
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V9fsSynthNode *node = synth_open->node;
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if (!node->attr->write) {
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errno = EPERM;
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return -1;
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}
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for (i = 0; i < iovcnt; i++) {
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wcount = node->attr->write(iov[i].iov_base, iov[i].iov_len,
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offset, node->private);
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offset += wcount;
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count += wcount;
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/* If we wrote less than requested. we are done */
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if (wcount < iov[i].iov_len) {
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break;
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}
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}
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return count;
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}
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static ssize_t v9fs_synth_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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int i, count = 0, rcount;
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V9fsSynthOpenState *synth_open = fs->private;
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V9fsSynthNode *node = synth_open->node;
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if (!node->attr->read) {
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errno = EPERM;
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return -1;
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}
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for (i = 0; i < iovcnt; i++) {
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rcount = node->attr->read(iov[i].iov_base, iov[i].iov_len,
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offset, node->private);
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offset += rcount;
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count += rcount;
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/* If we read less than requested. we are done */
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if (rcount < iov[i].iov_len) {
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break;
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}
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}
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return count;
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}
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static int v9fs_synth_truncate(FsContext *ctx, V9fsPath *path, off_t offset)
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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 int v9fs_synth_chmod(FsContext *fs_ctx, V9fsPath *path, FsCred *credp)
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{
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errno = EPERM;
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return -1;
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}
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static int v9fs_synth_mknod(FsContext *fs_ctx, V9fsPath *path,
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const char *buf, FsCred *credp)
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{
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errno = EPERM;
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return -1;
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}
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static int v9fs_synth_mkdir(FsContext *fs_ctx, V9fsPath *path,
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const char *buf, FsCred *credp)
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{
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errno = EPERM;
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return -1;
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}
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static ssize_t v9fs_synth_readlink(FsContext *fs_ctx, V9fsPath *path,
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char *buf, size_t bufsz)
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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 int v9fs_synth_symlink(FsContext *fs_ctx, const char *oldpath,
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V9fsPath *newpath, const char *buf, FsCred *credp)
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{
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errno = EPERM;
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return -1;
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}
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static int v9fs_synth_link(FsContext *fs_ctx, V9fsPath *oldpath,
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V9fsPath *newpath, const char *buf)
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{
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errno = EPERM;
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return -1;
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}
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static int v9fs_synth_rename(FsContext *ctx, const char *oldpath,
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const char *newpath)
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{
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errno = EPERM;
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return -1;
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}
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static int v9fs_synth_chown(FsContext *fs_ctx, V9fsPath *path, FsCred *credp)
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{
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errno = EPERM;
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return -1;
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}
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static int v9fs_synth_utimensat(FsContext *fs_ctx, V9fsPath *path,
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const struct timespec *buf)
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{
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errno = EPERM;
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return 0;
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}
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static int v9fs_synth_remove(FsContext *ctx, const char *path)
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{
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errno = EPERM;
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return -1;
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}
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static int v9fs_synth_fsync(FsContext *ctx, V9fsFidOpenState *fs, int datasync)
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{
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errno = ENOSYS;
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return 0;
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}
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static int v9fs_synth_statfs(FsContext *s, V9fsPath *fs_path,
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struct statfs *stbuf)
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{
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stbuf->f_type = 0xABCD;
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stbuf->f_bsize = 512;
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stbuf->f_blocks = 0;
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stbuf->f_files = v9fs_synth_node_count;
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stbuf->f_namelen = NAME_MAX;
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return 0;
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}
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static ssize_t v9fs_synth_lgetxattr(FsContext *ctx, V9fsPath *path,
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const char *name, void *value, size_t size)
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{
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errno = ENOTSUP;
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return -1;
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}
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static ssize_t v9fs_synth_llistxattr(FsContext *ctx, V9fsPath *path,
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void *value, size_t size)
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{
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errno = ENOTSUP;
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return -1;
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}
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static int v9fs_synth_lsetxattr(FsContext *ctx, V9fsPath *path,
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const char *name, void *value,
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size_t size, int flags)
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{
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errno = ENOTSUP;
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return -1;
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}
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static int v9fs_synth_lremovexattr(FsContext *ctx,
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V9fsPath *path, const char *name)
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{
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errno = ENOTSUP;
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return -1;
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}
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static int v9fs_synth_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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V9fsSynthNode *node;
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V9fsSynthNode *dir_node;
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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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dir_node = &v9fs_synth_root;
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} else {
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dir_node = *(V9fsSynthNode **)dir_path->data;
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}
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if (!strcmp(name, "/")) {
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node = dir_node;
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goto out;
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}
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/* search for the name in the childern */
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rcu_read_lock();
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QLIST_FOREACH(node, &dir_node->child, sibling) {
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if (!strcmp(node->name, name)) {
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break;
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}
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}
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rcu_read_unlock();
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if (!node) {
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errno = ENOENT;
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return -1;
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}
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out:
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/* Copy the node pointer to fid */
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target->data = g_malloc(sizeof(void *));
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memcpy(target->data, &node, sizeof(void *));
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target->size = sizeof(void *);
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return 0;
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}
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static int v9fs_synth_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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errno = EPERM;
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return -1;
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}
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static int v9fs_synth_unlinkat(FsContext *ctx, V9fsPath *dir,
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const char *name, int flags)
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{
|
|
errno = EPERM;
|
|
return -1;
|
|
}
|
|
|
|
static int v9fs_synth_init(FsContext *ctx)
|
|
{
|
|
QLIST_INIT(&v9fs_synth_root.child);
|
|
qemu_mutex_init(&v9fs_synth_mutex);
|
|
|
|
/* Add "." and ".." entries for root */
|
|
v9fs_add_dir_node(&v9fs_synth_root, v9fs_synth_root.attr->mode,
|
|
"..", v9fs_synth_root.attr, v9fs_synth_root.attr->inode);
|
|
v9fs_add_dir_node(&v9fs_synth_root, v9fs_synth_root.attr->mode,
|
|
".", v9fs_synth_root.attr, v9fs_synth_root.attr->inode);
|
|
|
|
/* Mark the subsystem is ready for use */
|
|
v9fs_synth_fs = 1;
|
|
return 0;
|
|
}
|
|
|
|
FileOperations synth_ops = {
|
|
.init = v9fs_synth_init,
|
|
.lstat = v9fs_synth_lstat,
|
|
.readlink = v9fs_synth_readlink,
|
|
.close = v9fs_synth_close,
|
|
.closedir = v9fs_synth_closedir,
|
|
.open = v9fs_synth_open,
|
|
.opendir = v9fs_synth_opendir,
|
|
.rewinddir = v9fs_synth_rewinddir,
|
|
.telldir = v9fs_synth_telldir,
|
|
.readdir_r = v9fs_synth_readdir_r,
|
|
.seekdir = v9fs_synth_seekdir,
|
|
.preadv = v9fs_synth_preadv,
|
|
.pwritev = v9fs_synth_pwritev,
|
|
.chmod = v9fs_synth_chmod,
|
|
.mknod = v9fs_synth_mknod,
|
|
.mkdir = v9fs_synth_mkdir,
|
|
.fstat = v9fs_synth_fstat,
|
|
.open2 = v9fs_synth_open2,
|
|
.symlink = v9fs_synth_symlink,
|
|
.link = v9fs_synth_link,
|
|
.truncate = v9fs_synth_truncate,
|
|
.rename = v9fs_synth_rename,
|
|
.chown = v9fs_synth_chown,
|
|
.utimensat = v9fs_synth_utimensat,
|
|
.remove = v9fs_synth_remove,
|
|
.fsync = v9fs_synth_fsync,
|
|
.statfs = v9fs_synth_statfs,
|
|
.lgetxattr = v9fs_synth_lgetxattr,
|
|
.llistxattr = v9fs_synth_llistxattr,
|
|
.lsetxattr = v9fs_synth_lsetxattr,
|
|
.lremovexattr = v9fs_synth_lremovexattr,
|
|
.name_to_path = v9fs_synth_name_to_path,
|
|
.renameat = v9fs_synth_renameat,
|
|
.unlinkat = v9fs_synth_unlinkat,
|
|
};
|