summaryrefslogtreecommitdiffstats
path: root/hw/9pfs/9p-synth.c
diff options
context:
space:
mode:
Diffstat (limited to 'hw/9pfs/9p-synth.c')
-rw-r--r--hw/9pfs/9p-synth.c659
1 files changed, 659 insertions, 0 deletions
diff --git a/hw/9pfs/9p-synth.c b/hw/9pfs/9p-synth.c
new file mode 100644
index 00000000..1c5813e4
--- /dev/null
+++ b/hw/9pfs/9p-synth.c
@@ -0,0 +1,659 @@
+/*
+ * 9p synthetic file system support
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ * Malahal Naineni <malahal@us.ibm.com>
+ * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+/*
+ * Not so fast! You might want to read the 9p developer docs first:
+ * https://wiki.qemu.org/Documentation/9p
+ */
+
+#include "qemu/osdep.h"
+#include "9p.h"
+#include "fsdev/qemu-fsdev.h"
+#include "9p-synth.h"
+#include "qemu/rcu.h"
+#include "qemu/rcu_queue.h"
+#include "qemu/cutils.h"
+#include "sysemu/qtest.h"
+
+/* Root node for synth file system */
+static V9fsSynthNode synth_root = {
+ .name = "/",
+ .actual_attr = {
+ .mode = 0555 | S_IFDIR,
+ .nlink = 1,
+ },
+ .attr = &synth_root.actual_attr,
+};
+
+static QemuMutex synth_mutex;
+static int synth_node_count;
+/* set to 1 when the synth fs is ready */
+static int synth_fs;
+
+static V9fsSynthNode *v9fs_add_dir_node(V9fsSynthNode *parent, int mode,
+ const char *name,
+ V9fsSynthNodeAttr *attr, int inode)
+{
+ V9fsSynthNode *node;
+
+ /* Add directory type and remove write bits */
+ mode = ((mode & 0777) | S_IFDIR) & ~(S_IWUSR | S_IWGRP | S_IWOTH);
+ node = g_new0(V9fsSynthNode, 1);
+ if (attr) {
+ /* We are adding .. or . entries */
+ node->attr = attr;
+ node->attr->nlink++;
+ } else {
+ node->attr = &node->actual_attr;
+ node->attr->inode = inode;
+ node->attr->nlink = 1;
+ /* We don't allow write to directories */
+ node->attr->mode = mode;
+ node->attr->write = NULL;
+ node->attr->read = NULL;
+ }
+ node->private = node;
+ pstrcpy(node->name, sizeof(node->name), name);
+ QLIST_INSERT_HEAD_RCU(&parent->child, node, sibling);
+ return node;
+}
+
+int qemu_v9fs_synth_mkdir(V9fsSynthNode *parent, int mode,
+ const char *name, V9fsSynthNode **result)
+{
+ int ret;
+ V9fsSynthNode *node, *tmp;
+
+ if (!synth_fs) {
+ return EAGAIN;
+ }
+ if (!name || (strlen(name) >= NAME_MAX)) {
+ return EINVAL;
+ }
+ if (!parent) {
+ parent = &synth_root;
+ }
+ QEMU_LOCK_GUARD(&synth_mutex);
+ QLIST_FOREACH(tmp, &parent->child, sibling) {
+ if (!strcmp(tmp->name, name)) {
+ ret = EEXIST;
+ return ret;
+ }
+ }
+ /* Add the name */
+ node = v9fs_add_dir_node(parent, mode, name, NULL, ++synth_node_count);
+ v9fs_add_dir_node(node, parent->attr->mode, "..",
+ parent->attr, parent->attr->inode);
+ v9fs_add_dir_node(node, node->attr->mode, ".",
+ node->attr, node->attr->inode);
+ *result = node;
+ ret = 0;
+ return ret;
+}
+
+int qemu_v9fs_synth_add_file(V9fsSynthNode *parent, int mode,
+ const char *name, v9fs_synth_read read,
+ v9fs_synth_write write, void *arg)
+{
+ int ret;
+ V9fsSynthNode *node, *tmp;
+
+ if (!synth_fs) {
+ return EAGAIN;
+ }
+ if (!name || (strlen(name) >= NAME_MAX)) {
+ return EINVAL;
+ }
+ if (!parent) {
+ parent = &synth_root;
+ }
+
+ QEMU_LOCK_GUARD(&synth_mutex);
+ QLIST_FOREACH(tmp, &parent->child, sibling) {
+ if (!strcmp(tmp->name, name)) {
+ ret = EEXIST;
+ return ret;
+ }
+ }
+ /* Add file type and remove write bits */
+ mode = ((mode & 0777) | S_IFREG);
+ node = g_new0(V9fsSynthNode, 1);
+ node->attr = &node->actual_attr;
+ node->attr->inode = ++synth_node_count;
+ node->attr->nlink = 1;
+ node->attr->read = read;
+ node->attr->write = write;
+ node->attr->mode = mode;
+ node->private = arg;
+ pstrcpy(node->name, sizeof(node->name), name);
+ QLIST_INSERT_HEAD_RCU(&parent->child, node, sibling);
+ ret = 0;
+ return ret;
+}
+
+static void synth_fill_statbuf(V9fsSynthNode *node, struct stat *stbuf)
+{
+ stbuf->st_dev = 0;
+ stbuf->st_ino = node->attr->inode;
+ stbuf->st_mode = node->attr->mode;
+ stbuf->st_nlink = node->attr->nlink;
+ stbuf->st_uid = 0;
+ stbuf->st_gid = 0;
+ stbuf->st_rdev = 0;
+ stbuf->st_size = 0;
+ stbuf->st_blksize = 0;
+ stbuf->st_blocks = 0;
+ stbuf->st_atime = 0;
+ stbuf->st_mtime = 0;
+ stbuf->st_ctime = 0;
+}
+
+static int synth_lstat(FsContext *fs_ctx,
+ V9fsPath *fs_path, struct stat *stbuf)
+{
+ V9fsSynthNode *node = *(V9fsSynthNode **)fs_path->data;
+
+ synth_fill_statbuf(node, stbuf);
+ return 0;
+}
+
+static int synth_fstat(FsContext *fs_ctx, int fid_type,
+ V9fsFidOpenState *fs, struct stat *stbuf)
+{
+ V9fsSynthOpenState *synth_open = fs->private;
+ synth_fill_statbuf(synth_open->node, stbuf);
+ return 0;
+}
+
+static int synth_opendir(FsContext *ctx,
+ V9fsPath *fs_path, V9fsFidOpenState *fs)
+{
+ V9fsSynthOpenState *synth_open;
+ V9fsSynthNode *node = *(V9fsSynthNode **)fs_path->data;
+
+ /*
+ * V9fsSynthOpenState contains 'struct dirent' which have OS-specific
+ * properties, thus it's zero cleared on allocation here and below
+ * in synth_open.
+ */
+ synth_open = g_new0(V9fsSynthOpenState, 1);
+ synth_open->node = node;
+ node->open_count++;
+ fs->private = synth_open;
+ return 0;
+}
+
+static int synth_closedir(FsContext *ctx, V9fsFidOpenState *fs)
+{
+ V9fsSynthOpenState *synth_open = fs->private;
+ V9fsSynthNode *node = synth_open->node;
+
+ node->open_count--;
+ g_free(synth_open);
+ fs->private = NULL;
+ return 0;
+}
+
+static off_t synth_telldir(FsContext *ctx, V9fsFidOpenState *fs)
+{
+ V9fsSynthOpenState *synth_open = fs->private;
+ return synth_open->offset;
+}
+
+static void synth_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
+{
+ V9fsSynthOpenState *synth_open = fs->private;
+ synth_open->offset = off;
+}
+
+static void synth_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
+{
+ synth_seekdir(ctx, fs, 0);
+}
+
+static void synth_direntry(V9fsSynthNode *node,
+ struct dirent *entry, off_t off)
+{
+ size_t sz = strlen(node->name) + 1;
+ /*
+ * 'entry' is always inside of V9fsSynthOpenState which have NAME_MAX
+ * back padding. Ensure we do not overflow it.
+ */
+ g_assert(sizeof(struct dirent) + NAME_MAX >=
+ offsetof(struct dirent, d_name) + sz);
+ memcpy(entry->d_name, node->name, sz);
+ entry->d_ino = node->attr->inode;
+#ifdef CONFIG_DARWIN
+ entry->d_seekoff = off + 1;
+#else
+ entry->d_off = off + 1;
+#endif
+}
+
+static struct dirent *synth_get_dentry(V9fsSynthNode *dir,
+ struct dirent *entry, off_t off)
+{
+ int i = 0;
+ V9fsSynthNode *node;
+
+ rcu_read_lock();
+ QLIST_FOREACH(node, &dir->child, sibling) {
+ /* This is the off child of the directory */
+ if (i == off) {
+ break;
+ }
+ i++;
+ }
+ rcu_read_unlock();
+ if (!node) {
+ /* end of directory */
+ return NULL;
+ }
+ synth_direntry(node, entry, off);
+ return entry;
+}
+
+static struct dirent *synth_readdir(FsContext *ctx, V9fsFidOpenState *fs)
+{
+ struct dirent *entry;
+ V9fsSynthOpenState *synth_open = fs->private;
+ V9fsSynthNode *node = synth_open->node;
+ entry = synth_get_dentry(node, &synth_open->dent, synth_open->offset);
+ if (entry) {
+ synth_open->offset++;
+ }
+ return entry;
+}
+
+static int synth_open(FsContext *ctx, V9fsPath *fs_path,
+ int flags, V9fsFidOpenState *fs)
+{
+ V9fsSynthOpenState *synth_open;
+ V9fsSynthNode *node = *(V9fsSynthNode **)fs_path->data;
+
+ synth_open = g_new0(V9fsSynthOpenState, 1);
+ synth_open->node = node;
+ node->open_count++;
+ fs->private = synth_open;
+ return 0;
+}
+
+static int synth_open2(FsContext *fs_ctx, V9fsPath *dir_path,
+ const char *name, int flags,
+ FsCred *credp, V9fsFidOpenState *fs)
+{
+ errno = ENOSYS;
+ return -1;
+}
+
+static int synth_close(FsContext *ctx, V9fsFidOpenState *fs)
+{
+ V9fsSynthOpenState *synth_open = fs->private;
+ V9fsSynthNode *node = synth_open->node;
+
+ node->open_count--;
+ g_free(synth_open);
+ fs->private = NULL;
+ return 0;
+}
+
+static ssize_t synth_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
+ const struct iovec *iov,
+ int iovcnt, off_t offset)
+{
+ int i, count = 0, wcount;
+ V9fsSynthOpenState *synth_open = fs->private;
+ V9fsSynthNode *node = synth_open->node;
+ if (!node->attr->write) {
+ errno = EPERM;
+ return -1;
+ }
+ for (i = 0; i < iovcnt; i++) {
+ wcount = node->attr->write(iov[i].iov_base, iov[i].iov_len,
+ offset, node->private);
+ offset += wcount;
+ count += wcount;
+ /* If we wrote less than requested. we are done */
+ if (wcount < iov[i].iov_len) {
+ break;
+ }
+ }
+ return count;
+}
+
+static ssize_t synth_preadv(FsContext *ctx, V9fsFidOpenState *fs,
+ const struct iovec *iov,
+ int iovcnt, off_t offset)
+{
+ int i, count = 0, rcount;
+ V9fsSynthOpenState *synth_open = fs->private;
+ V9fsSynthNode *node = synth_open->node;
+ if (!node->attr->read) {
+ errno = EPERM;
+ return -1;
+ }
+ for (i = 0; i < iovcnt; i++) {
+ rcount = node->attr->read(iov[i].iov_base, iov[i].iov_len,
+ offset, node->private);
+ offset += rcount;
+ count += rcount;
+ /* If we read less than requested. we are done */
+ if (rcount < iov[i].iov_len) {
+ break;
+ }
+ }
+ return count;
+}
+
+static int synth_truncate(FsContext *ctx, V9fsPath *path, off_t offset)
+{
+ errno = ENOSYS;
+ return -1;
+}
+
+static int synth_chmod(FsContext *fs_ctx, V9fsPath *path, FsCred *credp)
+{
+ errno = EPERM;
+ return -1;
+}
+
+static int synth_mknod(FsContext *fs_ctx, V9fsPath *path,
+ const char *buf, FsCred *credp)
+{
+ errno = EPERM;
+ return -1;
+}
+
+static int synth_mkdir(FsContext *fs_ctx, V9fsPath *path,
+ const char *buf, FsCred *credp)
+{
+ errno = EPERM;
+ return -1;
+}
+
+static ssize_t synth_readlink(FsContext *fs_ctx, V9fsPath *path,
+ char *buf, size_t bufsz)
+{
+ errno = ENOSYS;
+ return -1;
+}
+
+static int synth_symlink(FsContext *fs_ctx, const char *oldpath,
+ V9fsPath *newpath, const char *buf, FsCred *credp)
+{
+ errno = EPERM;
+ return -1;
+}
+
+static int synth_link(FsContext *fs_ctx, V9fsPath *oldpath,
+ V9fsPath *newpath, const char *buf)
+{
+ errno = EPERM;
+ return -1;
+}
+
+static int synth_rename(FsContext *ctx, const char *oldpath,
+ const char *newpath)
+{
+ errno = EPERM;
+ return -1;
+}
+
+static int synth_chown(FsContext *fs_ctx, V9fsPath *path, FsCred *credp)
+{
+ errno = EPERM;
+ return -1;
+}
+
+static int synth_utimensat(FsContext *fs_ctx, V9fsPath *path,
+ const struct timespec *buf)
+{
+ errno = EPERM;
+ return 0;
+}
+
+static int synth_remove(FsContext *ctx, const char *path)
+{
+ errno = EPERM;
+ return -1;
+}
+
+static int synth_fsync(FsContext *ctx, int fid_type,
+ V9fsFidOpenState *fs, int datasync)
+{
+ errno = ENOSYS;
+ return 0;
+}
+
+static int synth_statfs(FsContext *s, V9fsPath *fs_path,
+ struct statfs *stbuf)
+{
+ stbuf->f_type = 0xABCD;
+ stbuf->f_bsize = 512;
+ stbuf->f_blocks = 0;
+ stbuf->f_files = synth_node_count;
+#ifndef CONFIG_DARWIN
+ stbuf->f_namelen = NAME_MAX;
+#endif
+ return 0;
+}
+
+static ssize_t synth_lgetxattr(FsContext *ctx, V9fsPath *path,
+ const char *name, void *value, size_t size)
+{
+ errno = ENOTSUP;
+ return -1;
+}
+
+static ssize_t synth_llistxattr(FsContext *ctx, V9fsPath *path,
+ void *value, size_t size)
+{
+ errno = ENOTSUP;
+ return -1;
+}
+
+static int synth_lsetxattr(FsContext *ctx, V9fsPath *path,
+ const char *name, void *value,
+ size_t size, int flags)
+{
+ errno = ENOTSUP;
+ return -1;
+}
+
+static int synth_lremovexattr(FsContext *ctx,
+ V9fsPath *path, const char *name)
+{
+ errno = ENOTSUP;
+ return -1;
+}
+
+static int synth_name_to_path(FsContext *ctx, V9fsPath *dir_path,
+ const char *name, V9fsPath *target)
+{
+ V9fsSynthNode *node;
+ V9fsSynthNode *dir_node;
+
+ /* "." and ".." are not allowed */
+ if (!strcmp(name, ".") || !strcmp(name, "..")) {
+ errno = EINVAL;
+ return -1;
+
+ }
+ if (!dir_path) {
+ dir_node = &synth_root;
+ } else {
+ dir_node = *(V9fsSynthNode **)dir_path->data;
+ }
+ if (!strcmp(name, "/")) {
+ node = dir_node;
+ goto out;
+ }
+ /* search for the name in the childern */
+ rcu_read_lock();
+ QLIST_FOREACH(node, &dir_node->child, sibling) {
+ if (!strcmp(node->name, name)) {
+ break;
+ }
+ }
+ rcu_read_unlock();
+
+ if (!node) {
+ errno = ENOENT;
+ return -1;
+ }
+out:
+ /* Copy the node pointer to fid */
+ g_free(target->data);
+ target->data = g_memdup(&node, sizeof(void *));
+ target->size = sizeof(void *);
+ return 0;
+}
+
+static int synth_renameat(FsContext *ctx, V9fsPath *olddir,
+ const char *old_name, V9fsPath *newdir,
+ const char *new_name)
+{
+ errno = EPERM;
+ return -1;
+}
+
+static int synth_unlinkat(FsContext *ctx, V9fsPath *dir,
+ const char *name, int flags)
+{
+ errno = EPERM;
+ return -1;
+}
+
+static ssize_t v9fs_synth_qtest_write(void *buf, int len, off_t offset,
+ void *arg)
+{
+ return 1;
+}
+
+static ssize_t v9fs_synth_qtest_flush_write(void *buf, int len, off_t offset,
+ void *arg)
+{
+ bool should_block = !!*(uint8_t *)buf;
+
+ if (should_block) {
+ /* This will cause the server to call us again until we're cancelled */
+ errno = EINTR;
+ return -1;
+ }
+
+ return 1;
+}
+
+static int synth_init(FsContext *ctx, Error **errp)
+{
+ QLIST_INIT(&synth_root.child);
+ qemu_mutex_init(&synth_mutex);
+
+ /* Add "." and ".." entries for root */
+ v9fs_add_dir_node(&synth_root, synth_root.attr->mode,
+ "..", synth_root.attr, synth_root.attr->inode);
+ v9fs_add_dir_node(&synth_root, synth_root.attr->mode,
+ ".", synth_root.attr, synth_root.attr->inode);
+
+ /* Mark the subsystem is ready for use */
+ synth_fs = 1;
+
+ if (qtest_enabled()) {
+ V9fsSynthNode *node = NULL;
+ int i, ret;
+
+ /* Directory hierarchy for WALK test */
+ for (i = 0; i < P9_MAXWELEM; i++) {
+ char *name = g_strdup_printf(QTEST_V9FS_SYNTH_WALK_FILE, i);
+
+ ret = qemu_v9fs_synth_mkdir(node, 0700, name, &node);
+ assert(!ret);
+ g_free(name);
+ }
+
+ /* File for LOPEN test */
+ ret = qemu_v9fs_synth_add_file(NULL, 0, QTEST_V9FS_SYNTH_LOPEN_FILE,
+ NULL, NULL, ctx);
+ assert(!ret);
+
+ /* File for WRITE test */
+ ret = qemu_v9fs_synth_add_file(NULL, 0, QTEST_V9FS_SYNTH_WRITE_FILE,
+ NULL, v9fs_synth_qtest_write, ctx);
+ assert(!ret);
+
+ /* File for FLUSH test */
+ ret = qemu_v9fs_synth_add_file(NULL, 0, QTEST_V9FS_SYNTH_FLUSH_FILE,
+ NULL, v9fs_synth_qtest_flush_write,
+ ctx);
+ assert(!ret);
+
+ /* Directory for READDIR test */
+ {
+ V9fsSynthNode *dir = NULL;
+ ret = qemu_v9fs_synth_mkdir(
+ NULL, 0700, QTEST_V9FS_SYNTH_READDIR_DIR, &dir
+ );
+ assert(!ret);
+ for (i = 0; i < QTEST_V9FS_SYNTH_READDIR_NFILES; ++i) {
+ char *name = g_strdup_printf(
+ QTEST_V9FS_SYNTH_READDIR_FILE, i
+ );
+ ret = qemu_v9fs_synth_add_file(
+ dir, 0, name, NULL, NULL, ctx
+ );
+ assert(!ret);
+ g_free(name);
+ }
+ }
+ }
+
+ return 0;
+}
+
+FileOperations synth_ops = {
+ .init = synth_init,
+ .lstat = synth_lstat,
+ .readlink = synth_readlink,
+ .close = synth_close,
+ .closedir = synth_closedir,
+ .open = synth_open,
+ .opendir = synth_opendir,
+ .rewinddir = synth_rewinddir,
+ .telldir = synth_telldir,
+ .readdir = synth_readdir,
+ .seekdir = synth_seekdir,
+ .preadv = synth_preadv,
+ .pwritev = synth_pwritev,
+ .chmod = synth_chmod,
+ .mknod = synth_mknod,
+ .mkdir = synth_mkdir,
+ .fstat = synth_fstat,
+ .open2 = synth_open2,
+ .symlink = synth_symlink,
+ .link = synth_link,
+ .truncate = synth_truncate,
+ .rename = synth_rename,
+ .chown = synth_chown,
+ .utimensat = synth_utimensat,
+ .remove = synth_remove,
+ .fsync = synth_fsync,
+ .statfs = synth_statfs,
+ .lgetxattr = synth_lgetxattr,
+ .llistxattr = synth_llistxattr,
+ .lsetxattr = synth_lsetxattr,
+ .lremovexattr = synth_lremovexattr,
+ .name_to_path = synth_name_to_path,
+ .renameat = synth_renameat,
+ .unlinkat = synth_unlinkat,
+};
generated by cgit v1.2.3 (git 2.39.1) at 2025-07-28 07:49:59 +0000