diff options
Diffstat (limited to 'hw/9pfs/9p-synth.c')
| -rw-r--r-- | hw/9pfs/9p-synth.c | 573 |
1 files changed, 573 insertions, 0 deletions
diff --git a/hw/9pfs/9p-synth.c b/hw/9pfs/9p-synth.c new file mode 100644 index 0000000000..090ae0cd4c --- /dev/null +++ b/hw/9pfs/9p-synth.c @@ -0,0 +1,573 @@ +/* + * Virtio 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. + * + */ + +#include "hw/virtio/virtio.h" +#include "9p.h" +#include "9p-xattr.h" +#include "fsdev/qemu-fsdev.h" +#include "9p-synth.h" +#include "qemu/rcu.h" +#include "qemu/rcu_queue.h" +#include <sys/stat.h> + +/* Root node for synth file system */ +static V9fsSynthNode v9fs_synth_root = { + .name = "/", + .actual_attr = { + .mode = 0555 | S_IFDIR, + .nlink = 1, + }, + .attr = &v9fs_synth_root.actual_attr, +}; + +static QemuMutex v9fs_synth_mutex; +static int v9fs_synth_node_count; +/* set to 1 when the synth fs is ready */ +static int v9fs_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_malloc0(sizeof(V9fsSynthNode)); + 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 (!v9fs_synth_fs) { + return EAGAIN; + } + if (!name || (strlen(name) >= NAME_MAX)) { + return EINVAL; + } + if (!parent) { + parent = &v9fs_synth_root; + } + qemu_mutex_lock(&v9fs_synth_mutex); + QLIST_FOREACH(tmp, &parent->child, sibling) { + if (!strcmp(tmp->name, name)) { + ret = EEXIST; + goto err_out; + } + } + /* Add the name */ + node = v9fs_add_dir_node(parent, mode, name, NULL, v9fs_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; +err_out: + qemu_mutex_unlock(&v9fs_synth_mutex); + 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 (!v9fs_synth_fs) { + return EAGAIN; + } + if (!name || (strlen(name) >= NAME_MAX)) { + return EINVAL; + } + if (!parent) { + parent = &v9fs_synth_root; + } + + qemu_mutex_lock(&v9fs_synth_mutex); + QLIST_FOREACH(tmp, &parent->child, sibling) { + if (!strcmp(tmp->name, name)) { + ret = EEXIST; + goto err_out; + } + } + /* Add file type and remove write bits */ + mode = ((mode & 0777) | S_IFREG); + node = g_malloc0(sizeof(V9fsSynthNode)); + node->attr = &node->actual_attr; + node->attr->inode = v9fs_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; +err_out: + qemu_mutex_unlock(&v9fs_synth_mutex); + return ret; +} + +static void v9fs_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 v9fs_synth_lstat(FsContext *fs_ctx, + V9fsPath *fs_path, struct stat *stbuf) +{ + V9fsSynthNode *node = *(V9fsSynthNode **)fs_path->data; + + v9fs_synth_fill_statbuf(node, stbuf); + return 0; +} + +static int v9fs_synth_fstat(FsContext *fs_ctx, int fid_type, + V9fsFidOpenState *fs, struct stat *stbuf) +{ + V9fsSynthOpenState *synth_open = fs->private; + v9fs_synth_fill_statbuf(synth_open->node, stbuf); + return 0; +} + +static int v9fs_synth_opendir(FsContext *ctx, + V9fsPath *fs_path, V9fsFidOpenState *fs) +{ + V9fsSynthOpenState *synth_open; + V9fsSynthNode *node = *(V9fsSynthNode **)fs_path->data; + + synth_open = g_malloc(sizeof(*synth_open)); + synth_open->node = node; + node->open_count++; + fs->private = synth_open; + return 0; +} + +static int v9fs_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 v9fs_synth_telldir(FsContext *ctx, V9fsFidOpenState *fs) +{ + V9fsSynthOpenState *synth_open = fs->private; + return synth_open->offset; +} + +static void v9fs_synth_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off) +{ + V9fsSynthOpenState *synth_open = fs->private; + synth_open->offset = off; +} + +static void v9fs_synth_rewinddir(FsContext *ctx, V9fsFidOpenState *fs) +{ + v9fs_synth_seekdir(ctx, fs, 0); +} + +static void v9fs_synth_direntry(V9fsSynthNode *node, + struct dirent *entry, off_t off) +{ + strcpy(entry->d_name, node->name); + entry->d_ino = node->attr->inode; + entry->d_off = off + 1; +} + +static int v9fs_synth_get_dentry(V9fsSynthNode *dir, struct dirent *entry, + struct dirent **result, 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 */ + *result = NULL; + return 0; + } + v9fs_synth_direntry(node, entry, off); + *result = entry; + return 0; +} + +static int v9fs_synth_readdir_r(FsContext *ctx, V9fsFidOpenState *fs, + struct dirent *entry, struct dirent **result) +{ + int ret; + V9fsSynthOpenState *synth_open = fs->private; + V9fsSynthNode *node = synth_open->node; + ret = v9fs_synth_get_dentry(node, entry, result, synth_open->offset); + if (!ret && *result != NULL) { + synth_open->offset++; + } + return ret; +} + +static int v9fs_synth_open(FsContext *ctx, V9fsPath *fs_path, + int flags, V9fsFidOpenState *fs) +{ + V9fsSynthOpenState *synth_open; + V9fsSynthNode *node = *(V9fsSynthNode **)fs_path->data; + + synth_open = g_malloc(sizeof(*synth_open)); + synth_open->node = node; + node->open_count++; + fs->private = synth_open; + return 0; +} + +static int v9fs_synth_open2(FsContext *fs_ctx, V9fsPath *dir_path, + const char *name, int flags, + FsCred *credp, V9fsFidOpenState *fs) +{ + errno = ENOSYS; + return -1; +} + +static int v9fs_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 v9fs_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 v9fs_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 v9fs_synth_truncate(FsContext *ctx, V9fsPath *path, off_t offset) +{ + errno = ENOSYS; + return -1; +} + +static int v9fs_synth_chmod(FsContext *fs_ctx, V9fsPath *path, FsCred *credp) +{ + errno = EPERM; + return -1; +} + +static int v9fs_synth_mknod(FsContext *fs_ctx, V9fsPath *path, + const char *buf, FsCred *credp) +{ + errno = EPERM; + return -1; +} + +static int v9fs_synth_mkdir(FsContext *fs_ctx, V9fsPath *path, + const char *buf, FsCred *credp) +{ + errno = EPERM; + return -1; +} + +static ssize_t v9fs_synth_readlink(FsContext *fs_ctx, V9fsPath *path, + char *buf, size_t bufsz) +{ + errno = ENOSYS; + return -1; +} + +static int v9fs_synth_symlink(FsContext *fs_ctx, const char *oldpath, + V9fsPath *newpath, const char *buf, FsCred *credp) +{ + errno = EPERM; + return -1; +} + +static int v9fs_synth_link(FsContext *fs_ctx, V9fsPath *oldpath, + V9fsPath *newpath, const char *buf) +{ + errno = EPERM; + return -1; +} + +static int v9fs_synth_rename(FsContext *ctx, const char *oldpath, + const char *newpath) +{ + errno = EPERM; + return -1; +} + +static int v9fs_synth_chown(FsContext *fs_ctx, V9fsPath *path, FsCred *credp) +{ + errno = EPERM; + return -1; +} + +static int v9fs_synth_utimensat(FsContext *fs_ctx, V9fsPath *path, + const struct timespec *buf) +{ + errno = EPERM; + return 0; +} + +static int v9fs_synth_remove(FsContext *ctx, const char *path) +{ + errno = EPERM; + return -1; +} + +static int v9fs_synth_fsync(FsContext *ctx, int fid_type, + V9fsFidOpenState *fs, int datasync) +{ + errno = ENOSYS; + return 0; +} + +static int v9fs_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 = v9fs_synth_node_count; + stbuf->f_namelen = NAME_MAX; + return 0; +} + +static ssize_t v9fs_synth_lgetxattr(FsContext *ctx, V9fsPath *path, + const char *name, void *value, size_t size) +{ + errno = ENOTSUP; + return -1; +} + +static ssize_t v9fs_synth_llistxattr(FsContext *ctx, V9fsPath *path, + void *value, size_t size) +{ + errno = ENOTSUP; + return -1; +} + +static int v9fs_synth_lsetxattr(FsContext *ctx, V9fsPath *path, + const char *name, void *value, + size_t size, int flags) +{ + errno = ENOTSUP; + return -1; +} + +static int v9fs_synth_lremovexattr(FsContext *ctx, + V9fsPath *path, const char *name) +{ + errno = ENOTSUP; + return -1; +} + +static int v9fs_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 = &v9fs_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 */ + target->data = g_malloc(sizeof(void *)); + memcpy(target->data, &node, sizeof(void *)); + target->size = sizeof(void *); + return 0; +} + +static int v9fs_synth_renameat(FsContext *ctx, V9fsPath *olddir, + const char *old_name, V9fsPath *newdir, + const char *new_name) +{ + errno = EPERM; + return -1; +} + +static int v9fs_synth_unlinkat(FsContext *ctx, V9fsPath *dir, + const char *name, int flags) +{ + 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, +}; 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