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authorAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>2011-08-02 11:35:54 +0530
committerAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>2011-09-22 21:38:53 +0530
commit5f5422258e1f50f871bafcc5bfb2b498f414a310 (patch)
treed2a3ff07b94f553d3afd2ff8e63bb91ab2ca20e5 /hw/9pfs
parentbccacf6c7920ee46ec4063c4bd9469eb3ec4e253 (diff)
hw/9pfs: Add handle based fs driver
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Diffstat (limited to 'hw/9pfs')
-rw-r--r--hw/9pfs/virtio-9p-handle.c611
1 files changed, 611 insertions, 0 deletions
diff --git a/hw/9pfs/virtio-9p-handle.c b/hw/9pfs/virtio-9p-handle.c
new file mode 100644
index 0000000000..5c8b5ed471
--- /dev/null
+++ b/hw/9pfs/virtio-9p-handle.c
@@ -0,0 +1,611 @@
+/*
+ * Virtio 9p handle callback
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ * 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.h"
+#include "virtio-9p.h"
+#include "virtio-9p-xattr.h"
+#include <arpa/inet.h>
+#include <pwd.h>
+#include <grp.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <attr/xattr.h>
+#include <unistd.h>
+
+struct handle_data {
+ int mountfd;
+ int handle_bytes;
+};
+
+#if __GLIBC__ <= 2 && __GLIBC_MINOR__ < 14
+struct file_handle {
+ unsigned int handle_bytes;
+ int handle_type;
+ unsigned char handle[0];
+};
+#endif
+
+#ifndef AT_EMPTY_PATH
+#define AT_EMPTY_PATH 0x1000 /* Allow empty relative pathname */
+#endif
+#ifndef O_PATH
+#define O_PATH 010000000
+#endif
+
+#ifndef __NR_name_to_handle_at
+#if defined(__i386__)
+#define __NR_name_to_handle_at 341
+#define __NR_open_by_handle_at 342
+#elif defined(__x86_64__)
+#define __NR_name_to_handle_at 303
+#define __NR_open_by_handle_at 304
+#endif
+#endif
+
+#ifdef __NR_name_to_handle_at
+static inline int name_to_handle(int dirfd, const char *name,
+ struct file_handle *fh, int *mnt_id, int flags)
+{
+ return syscall(__NR_name_to_handle_at, dirfd, name, fh, mnt_id, flags);
+}
+
+static inline int open_by_handle(int mountfd, const char *fh, int flags)
+{
+ return syscall(__NR_open_by_handle_at, mountfd, fh, flags);
+}
+#else
+static inline int name_to_handle(int dirfd, const char *name,
+ struct file_handle *fh, int *mnt_id, int flags)
+{
+ errno = ENOSYS;
+ return -1;
+}
+
+static inline int open_by_handle(int mountfd, const char *fh, int flags)
+{
+ errno = ENOSYS;
+ return -1;
+}
+#endif
+
+static int handle_update_file_cred(int dirfd, const char *name, FsCred *credp)
+{
+ int fd, ret;
+ fd = openat(dirfd, name, O_NONBLOCK | O_NOFOLLOW);;
+ if (fd < 0) {
+ return fd;
+ }
+ ret = fchmod(fd, credp->fc_mode & 07777);
+ if (ret < 0) {
+ goto err_out;
+ }
+ ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
+err_out:
+ close(fd);
+ return ret;
+}
+
+
+static int handle_lstat(FsContext *fs_ctx, V9fsPath *fs_path,
+ struct stat *stbuf)
+{
+ int fd, ret;
+ struct handle_data *data = (struct handle_data *)fs_ctx->private;
+
+ fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
+ if (fd < 0) {
+ return fd;
+ }
+ ret = fstatat(fd, "", stbuf, AT_EMPTY_PATH);
+ close(fd);
+ return ret;
+}
+
+static ssize_t handle_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
+ char *buf, size_t bufsz)
+{
+ int fd, ret;
+ struct handle_data *data = (struct handle_data *)fs_ctx->private;
+
+ fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
+ if (fd < 0) {
+ return fd;
+ }
+ ret = readlinkat(fd, "", buf, bufsz);
+ close(fd);
+ return ret;
+}
+
+static int handle_close(FsContext *ctx, int fd)
+{
+ return close(fd);
+}
+
+static int handle_closedir(FsContext *ctx, DIR *dir)
+{
+ return closedir(dir);
+}
+
+static int handle_open(FsContext *ctx, V9fsPath *fs_path, int flags)
+{
+ struct handle_data *data = (struct handle_data *)ctx->private;
+
+ return open_by_handle(data->mountfd, fs_path->data, flags);
+}
+
+static DIR *handle_opendir(FsContext *ctx, V9fsPath *fs_path)
+{
+ int fd;
+ fd = handle_open(ctx, fs_path, O_DIRECTORY);
+ if (fd < 0) {
+ return NULL;
+ }
+ return fdopendir(fd);
+}
+
+static void handle_rewinddir(FsContext *ctx, DIR *dir)
+{
+ return rewinddir(dir);
+}
+
+static off_t handle_telldir(FsContext *ctx, DIR *dir)
+{
+ return telldir(dir);
+}
+
+static int handle_readdir_r(FsContext *ctx, DIR *dir, struct dirent *entry,
+ struct dirent **result)
+{
+ return readdir_r(dir, entry, result);
+}
+
+static void handle_seekdir(FsContext *ctx, DIR *dir, off_t off)
+{
+ return seekdir(dir, off);
+}
+
+static ssize_t handle_preadv(FsContext *ctx, int fd, const struct iovec *iov,
+ int iovcnt, off_t offset)
+{
+#ifdef CONFIG_PREADV
+ return preadv(fd, iov, iovcnt, offset);
+#else
+ int err = lseek(fd, offset, SEEK_SET);
+ if (err == -1) {
+ return err;
+ } else {
+ return readv(fd, iov, iovcnt);
+ }
+#endif
+}
+
+static ssize_t handle_pwritev(FsContext *ctx, int fd, const struct iovec *iov,
+ int iovcnt, off_t offset)
+{
+#ifdef CONFIG_PREADV
+ return pwritev(fd, iov, iovcnt, offset);
+#else
+ int err = lseek(fd, offset, SEEK_SET);
+ if (err == -1) {
+ return err;
+ } else {
+ return writev(fd, iov, iovcnt);
+ }
+#endif
+}
+
+static int handle_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
+{
+ int fd, ret;
+ struct handle_data *data = (struct handle_data *)fs_ctx->private;
+
+ fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
+ if (fd < 0) {
+ return fd;
+ }
+ ret = fchmod(fd, credp->fc_mode);
+ close(fd);
+ return ret;
+}
+
+static int handle_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
+ const char *name, FsCred *credp)
+{
+ int dirfd, ret;
+ struct handle_data *data = (struct handle_data *)fs_ctx->private;
+
+ dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
+ if (dirfd < 0) {
+ return dirfd;
+ }
+ ret = mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev);
+ if (!ret) {
+ ret = handle_update_file_cred(dirfd, name, credp);
+ }
+ close(dirfd);
+ return ret;
+}
+
+static int handle_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
+ const char *name, FsCred *credp)
+{
+ int dirfd, ret;
+ struct handle_data *data = (struct handle_data *)fs_ctx->private;
+
+ dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
+ if (dirfd < 0) {
+ return dirfd;
+ }
+ ret = mkdirat(dirfd, name, credp->fc_mode);
+ if (!ret) {
+ ret = handle_update_file_cred(dirfd, name, credp);
+ }
+ close(dirfd);
+ return ret;
+}
+
+static int handle_fstat(FsContext *fs_ctx, int fd, struct stat *stbuf)
+{
+ return fstat(fd, stbuf);
+}
+
+static int handle_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
+ int flags, FsCred *credp)
+{
+ int ret;
+ int dirfd, fd;
+ struct handle_data *data = (struct handle_data *)fs_ctx->private;
+
+ dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
+ if (dirfd < 0) {
+ return dirfd;
+ }
+ fd = openat(dirfd, name, flags | O_NOFOLLOW, credp->fc_mode);
+ if (fd >= 0) {
+ ret = handle_update_file_cred(dirfd, name, credp);
+ if (ret < 0) {
+ close(fd);
+ fd = ret;
+ }
+ }
+ close(dirfd);
+ return fd;
+}
+
+
+static int handle_symlink(FsContext *fs_ctx, const char *oldpath,
+ V9fsPath *dir_path, const char *name, FsCred *credp)
+{
+ int fd, dirfd, ret;
+ struct handle_data *data = (struct handle_data *)fs_ctx->private;
+
+ dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
+ if (dirfd < 0) {
+ return dirfd;
+ }
+ ret = symlinkat(oldpath, dirfd, name);
+ if (!ret) {
+ fd = openat(dirfd, name, O_PATH | O_NOFOLLOW);
+ if (fd < 0) {
+ ret = fd;
+ goto err_out;
+ }
+ ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
+ close(fd);
+ }
+err_out:
+ close(dirfd);
+ return ret;
+}
+
+static int handle_link(FsContext *ctx, V9fsPath *oldpath,
+ V9fsPath *dirpath, const char *name)
+{
+ int oldfd, newdirfd, ret;
+ struct handle_data *data = (struct handle_data *)ctx->private;
+
+ oldfd = open_by_handle(data->mountfd, oldpath->data, O_PATH);
+ if (oldfd < 0) {
+ return oldfd;
+ }
+ newdirfd = open_by_handle(data->mountfd, dirpath->data, O_PATH);
+ if (newdirfd < 0) {
+ close(oldfd);
+ return newdirfd;
+ }
+ ret = linkat(oldfd, "", newdirfd, name, AT_EMPTY_PATH);
+ close(newdirfd);
+ close(oldfd);
+ return ret;
+}
+
+static int handle_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
+{
+ int fd, ret;
+ struct handle_data *data = (struct handle_data *)ctx->private;
+
+ fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK | O_WRONLY);
+ if (fd < 0) {
+ return fd;
+ }
+ ret = ftruncate(fd, size);
+ close(fd);
+ return ret;
+}
+
+static int handle_rename(FsContext *ctx, const char *oldpath,
+ const char *newpath)
+{
+ errno = EOPNOTSUPP;
+ return -1;
+}
+
+static int handle_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
+{
+ int fd, ret;
+ struct handle_data *data = (struct handle_data *)fs_ctx->private;
+
+ fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
+ if (fd < 0) {
+ return fd;
+ }
+ ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
+ close(fd);
+ return ret;
+}
+
+static int handle_utimensat(FsContext *ctx, V9fsPath *fs_path,
+ const struct timespec *buf)
+{
+ int fd, ret;
+ struct handle_data *data = (struct handle_data *)ctx->private;
+
+ fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
+ if (fd < 0) {
+ return fd;
+ }
+ ret = futimens(fd, buf);
+ close(fd);
+ return ret;
+}
+
+static int handle_remove(FsContext *ctx, const char *path)
+{
+ errno = EOPNOTSUPP;
+ return -1;
+}
+
+static int handle_fsync(FsContext *ctx, int fd, int datasync)
+{
+ if (datasync) {
+ return qemu_fdatasync(fd);
+ } else {
+ return fsync(fd);
+ }
+}
+
+static int handle_statfs(FsContext *ctx, V9fsPath *fs_path,
+ struct statfs *stbuf)
+{
+ int fd, ret;
+ struct handle_data *data = (struct handle_data *)ctx->private;
+
+ fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
+ if (fd < 0) {
+ return fd;
+ }
+ ret = fstatfs(fd, stbuf);
+ close(fd);
+ return ret;
+}
+
+static ssize_t handle_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
+ const char *name, void *value, size_t size)
+{
+ int fd, ret;
+ struct handle_data *data = (struct handle_data *)ctx->private;
+
+ fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
+ if (fd < 0) {
+ return fd;
+ }
+ ret = fgetxattr(fd, name, value, size);
+ close(fd);
+ return ret;
+}
+
+static ssize_t handle_llistxattr(FsContext *ctx, V9fsPath *fs_path,
+ void *value, size_t size)
+{
+ int fd, ret;
+ struct handle_data *data = (struct handle_data *)ctx->private;
+
+ fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
+ if (fd < 0) {
+ return fd;
+ }
+ ret = flistxattr(fd, value, size);
+ close(fd);
+ return ret;
+}
+
+static int handle_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
+ void *value, size_t size, int flags)
+{
+ int fd, ret;
+ struct handle_data *data = (struct handle_data *)ctx->private;
+
+ fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
+ if (fd < 0) {
+ return fd;
+ }
+ ret = fsetxattr(fd, name, value, size, flags);
+ close(fd);
+ return ret;
+}
+
+static int handle_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
+ const char *name)
+{
+ int fd, ret;
+ struct handle_data *data = (struct handle_data *)ctx->private;
+
+ fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
+ if (fd < 0) {
+ return fd;
+ }
+ ret = fremovexattr(fd, name);
+ close(fd);
+ return ret;
+}
+
+static int handle_name_to_path(FsContext *ctx, V9fsPath *dir_path,
+ const char *name, V9fsPath *target)
+{
+ char buffer[PATH_MAX];
+ struct file_handle *fh;
+ int dirfd, ret, mnt_id;
+ struct handle_data *data = (struct handle_data *)ctx->private;
+
+ /* "." and ".." are not allowed */
+ if (!strcmp(name, ".") || !strcmp(name, "..")) {
+ errno = EINVAL;
+ return -1;
+
+ }
+ if (dir_path) {
+ dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
+ } else {
+ /* relative to export root */
+ dirfd = open(rpath(ctx, ".", buffer), O_DIRECTORY);
+ }
+ if (dirfd < 0) {
+ return dirfd;
+ }
+ fh = g_malloc(sizeof(struct file_handle) + data->handle_bytes);
+ fh->handle_bytes = data->handle_bytes;
+ /* add a "./" at the begining of the path */
+ snprintf(buffer, PATH_MAX, "./%s", name);
+ /* flag = 0 imply don't follow symlink */
+ ret = name_to_handle(dirfd, buffer, fh, &mnt_id, 0);
+ if (!ret) {
+ target->data = (char *)fh;
+ target->size = sizeof(struct file_handle) + data->handle_bytes;
+ } else {
+ g_free(fh);
+ }
+ close(dirfd);
+ return ret;
+}
+
+static int handle_renameat(FsContext *ctx, V9fsPath *olddir,
+ const char *old_name, V9fsPath *newdir,
+ const char *new_name)
+{
+ int olddirfd, newdirfd, ret;
+ struct handle_data *data = (struct handle_data *)ctx->private;
+
+ olddirfd = open_by_handle(data->mountfd, olddir->data, O_PATH);
+ if (olddirfd < 0) {
+ return olddirfd;
+ }
+ newdirfd = open_by_handle(data->mountfd, newdir->data, O_PATH);
+ if (newdirfd < 0) {
+ close(olddirfd);
+ return newdirfd;
+ }
+ ret = renameat(olddirfd, old_name, newdirfd, new_name);
+ close(newdirfd);
+ close(olddirfd);
+ return ret;
+}
+
+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,
+};