[qemu.git] / hw / 9pfs / 9p-handle.c

/*
 * 9p handle callback
 *
 * Copyright IBM, Corp. 2011
 *
 * Authors:
 *    Aneesh Kumar K.V <[email protected]>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 *
 */

#include "qemu/osdep.h"
#include "9p.h"
#include "9p-xattr.h"
#include <arpa/inet.h>
#include <pwd.h>
#include <grp.h>
#include <sys/socket.h>
#include <sys/un.h>
#include "qemu/xattr.h"
#include "qemu/cutils.h"
#include "qemu/error-report.h"
#include <linux/fs.h>
#ifdef CONFIG_LINUX_MAGIC_H
#include <linux/magic.h>
#endif
#include <sys/ioctl.h>

#ifndef XFS_SUPER_MAGIC
#define XFS_SUPER_MAGIC  0x58465342
#endif
#ifndef EXT2_SUPER_MAGIC
#define EXT2_SUPER_MAGIC 0xEF53
#endif
#ifndef REISERFS_SUPER_MAGIC
#define REISERFS_SUPER_MAGIC 0x52654973
#endif
#ifndef BTRFS_SUPER_MAGIC
#define BTRFS_SUPER_MAGIC 0x9123683E
#endif

struct handle_data {
    int mountfd;
    int handle_bytes;
};

static inline int name_to_handle(int dirfd, const char *name,
                                 struct file_handle *fh, int *mnt_id, int flags)
{
    return name_to_handle_at(dirfd, name, fh, mnt_id, flags);
}

static inline int open_by_handle(int mountfd, const char *fh, int flags)
{
    return open_by_handle_at(mountfd, (struct file_handle *)fh, flags);
}

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 = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
    if (ret < 0) {
        goto err_out;
    }
    ret = fchmod(fd, credp->fc_mode & 07777);
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, V9fsFidOpenState *fs)
{
    return close(fs->fd);
}

static int handle_closedir(FsContext *ctx, V9fsFidOpenState *fs)
{
    return closedir(fs->dir.stream);
}

static int handle_open(FsContext *ctx, V9fsPath *fs_path,
                       int flags, V9fsFidOpenState *fs)
{
    struct handle_data *data = (struct handle_data *)ctx->private;

    fs->fd = open_by_handle(data->mountfd, fs_path->data, flags);
    return fs->fd;
}

static int handle_opendir(FsContext *ctx,
                          V9fsPath *fs_path, V9fsFidOpenState *fs)
{
    int ret;
    ret = handle_open(ctx, fs_path, O_DIRECTORY, fs);
    if (ret < 0) {
        return -1;
    }
    fs->dir.stream = fdopendir(ret);
    if (!fs->dir.stream) {
        return -1;
    }
    return 0;
}

static void handle_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
{
    rewinddir(fs->dir.stream);
}

static off_t handle_telldir(FsContext *ctx, V9fsFidOpenState *fs)
{
    return telldir(fs->dir.stream);
}

static struct dirent *handle_readdir(FsContext *ctx, V9fsFidOpenState *fs)
{
    return readdir(fs->dir.stream);
}

static void handle_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
{
    seekdir(fs->dir.stream, off);
}

static ssize_t handle_preadv(FsContext *ctx, V9fsFidOpenState *fs,
                             const struct iovec *iov,
                             int iovcnt, off_t offset)
{
#ifdef CONFIG_PREADV
    return preadv(fs->fd, iov, iovcnt, offset);
#else
    int err = lseek(fs->fd, offset, SEEK_SET);
    if (err == -1) {
        return err;
    } else {
        return readv(fs->fd, iov, iovcnt);
    }
#endif
}

static ssize_t handle_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
                              const struct iovec *iov,
                              int iovcnt, off_t offset)
{
    ssize_t ret;
#ifdef CONFIG_PREADV
    ret = pwritev(fs->fd, iov, iovcnt, offset);
#else
    int err = lseek(fs->fd, offset, SEEK_SET);
    if (err == -1) {
        return err;
    } else {
        ret = writev(fs->fd, iov, iovcnt);
    }
#endif
#ifdef CONFIG_SYNC_FILE_RANGE
    if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
        /*
         * Initiate a writeback. This is not a data integrity sync.
         * We want to ensure that we don't leave dirty pages in the cache
         * after write when writeout=immediate is sepcified.
         */
        sync_file_range(fs->fd, offset, ret,
                        SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
    }
#endif
    return ret;
}

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 fid_type,
                        V9fsFidOpenState *fs, struct stat *stbuf)
{
    int fd;

    if (fid_type == P9_FID_DIR) {
        fd = dirfd(fs->dir.stream);
    } else {
        fd = fs->fd;
    }
    return fstat(fd, stbuf);
}

static int handle_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
                        int flags, FsCred *credp, V9fsFidOpenState *fs)
{
    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;
        } else {
            fs->fd = fd;
        }
    }
    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 ret;
#ifdef CONFIG_UTIMENSAT
    int fd;
    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);
#else
    ret = -1;
    errno = ENOSYS;
#endif
    return ret;
}

static int handle_remove(FsContext *ctx, const char *path)
{
    errno = EOPNOTSUPP;
    return -1;
}

static int handle_fsync(FsContext *ctx, int fid_type,
                        V9fsFidOpenState *fs, int datasync)
{
    int fd;

    if (fid_type == P9_FID_DIR) {
        fd = dirfd(fs->dir.stream);
    } else {
        fd = fs->fd;
    }

    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;
    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 */
        buffer = rpath(ctx, ".");
        dirfd = open(buffer, O_DIRECTORY);
        g_free(buffer);
    }
    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 beginning of the path */
    buffer = g_strdup_printf("./%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);
    g_free(buffer);
    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;
    int rflags;

    dirfd = open_by_handle(data->mountfd, dir->data, O_PATH);
    if (dirfd < 0) {
        return dirfd;
    }

    rflags = 0;
    if (flags & P9_DOTL_AT_REMOVEDIR) {
        rflags |= AT_REMOVEDIR;
    }

    ret = unlinkat(dirfd, name, rflags);

    close(dirfd);
    return ret;
}

static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
                                 mode_t st_mode, uint64_t *st_gen)
{
#ifdef FS_IOC_GETVERSION
    int err;
    V9fsFidOpenState fid_open;

    /*
     * Do not try to open special files like device nodes, fifos etc
     * We can get fd for regular files and directories only
     */
    if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
        errno = ENOTTY;
        return -1;
    }
    err = handle_open(ctx, path, O_RDONLY, &fid_open);
    if (err < 0) {
        return err;
    }
    err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
    handle_close(ctx, &fid_open);
    return err;
#else
    errno = ENOTTY;
    return -1;
#endif
}

static int handle_init(FsContext *ctx)
{
    int ret, mnt_id;
    struct statfs stbuf;
    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;
    }
    ret = statfs(ctx->fs_root, &stbuf);
    if (!ret) {
        switch (stbuf.f_type) {
        case EXT2_SUPER_MAGIC:
        case BTRFS_SUPER_MAGIC:
        case REISERFS_SUPER_MAGIC:
        case XFS_SUPER_MAGIC:
            ctx->exops.get_st_gen = handle_ioc_getversion;
            break;
        }
    }
    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;
}

static void handle_cleanup(FsContext *ctx)
{
    struct handle_data *data = ctx->private;

    close(data->mountfd);
    g_free(data);
}

static int handle_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
{
    const char *sec_model = qemu_opt_get(opts, "security_model");
    const char *path = qemu_opt_get(opts, "path");

    if (sec_model) {
        error_report("Invalid argument security_model specified with handle fsdriver");
        return -1;
    }

    if (!path) {
        error_report("fsdev: No path specified");
        return -1;
    }
    fse->path = g_strdup(path);
    return 0;

}

FileOperations handle_ops = {
    .parse_opts   = handle_parse_opts,
    .init         = handle_init,
    .cleanup      = handle_cleanup,
    .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      = handle_readdir,
    .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,
};
Commit	Line	Data
5f542225	1	/*
3b9ca046	2	* 9p handle callback
5f542225 AK	3	*
	4	* Copyright IBM, Corp. 2011
	5	*
	6	* Authors:
	7	* Aneesh Kumar K.V <[email protected]>
	8	*
	9	* This work is licensed under the terms of the GNU GPL, version 2. See
	10	* the COPYING file in the top-level directory.
	11	*
	12	*/
	13
fbc04127	14	#include "qemu/osdep.h"
ebe74f8b	15	#include "9p.h"
267ae092	16	#include "9p-xattr.h"
5f542225 AK	17	#include <arpa/inet.h>
	18	#include <pwd.h>
	19	#include <grp.h>
	20	#include <sys/socket.h>
	21	#include <sys/un.h>
1de7afc9	22	#include "qemu/xattr.h"
f348b6d1	23	#include "qemu/cutils.h"
63325b18	24	#include "qemu/error-report.h"
edb9eb73 HPB	25	#include <linux/fs.h>
	26	#ifdef CONFIG_LINUX_MAGIC_H
	27	#include <linux/magic.h>
	28	#endif
	29	#include <sys/ioctl.h>
	30
	31	#ifndef XFS_SUPER_MAGIC
	32	#define XFS_SUPER_MAGIC 0x58465342
	33	#endif
	34	#ifndef EXT2_SUPER_MAGIC
	35	#define EXT2_SUPER_MAGIC 0xEF53
	36	#endif
	37	#ifndef REISERFS_SUPER_MAGIC
	38	#define REISERFS_SUPER_MAGIC 0x52654973
	39	#endif
	40	#ifndef BTRFS_SUPER_MAGIC
	41	#define BTRFS_SUPER_MAGIC 0x9123683E
	42	#endif
5f542225 AK	43
	44	struct handle_data {
	45	int mountfd;
	46	int handle_bytes;
	47	};
	48
d2042378 AK	49	static inline int name_to_handle(int dirfd, const char *name,
	50	struct file_handle fh, int mnt_id, int flags)
	51	{
	52	return name_to_handle_at(dirfd, name, fh, mnt_id, flags);
	53	}
	54
	55	static inline int open_by_handle(int mountfd, const char *fh, int flags)
	56	{
	57	return open_by_handle_at(mountfd, (struct file_handle *)fh, flags);
	58	}
5f542225 AK	59
	60	static int handle_update_file_cred(int dirfd, const char name, FsCred credp)
	61	{
	62	int fd, ret;
3a93113a	63	fd = openat(dirfd, name, O_NONBLOCK \| O_NOFOLLOW);
5f542225 AK	64	if (fd < 0) {
	65	return fd;
	66	}
2d40564a	67	ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
5f542225 AK	68	if (ret < 0) {
	69	goto err_out;
	70	}
2d40564a	71	ret = fchmod(fd, credp->fc_mode & 07777);
5f542225 AK	72	err_out:
	73	close(fd);
	74	return ret;
	75	}
	76
	77
	78	static int handle_lstat(FsContext fs_ctx, V9fsPath fs_path,
	79	struct stat *stbuf)
	80	{
	81	int fd, ret;
	82	struct handle_data data = (struct handle_data )fs_ctx->private;
	83
	84	fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
	85	if (fd < 0) {
	86	return fd;
	87	}
	88	ret = fstatat(fd, "", stbuf, AT_EMPTY_PATH);
	89	close(fd);
	90	return ret;
	91	}
	92
	93	static ssize_t handle_readlink(FsContext fs_ctx, V9fsPath fs_path,
	94	char *buf, size_t bufsz)
	95	{
	96	int fd, ret;
	97	struct handle_data data = (struct handle_data )fs_ctx->private;
	98
	99	fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
	100	if (fd < 0) {
	101	return fd;
	102	}
	103	ret = readlinkat(fd, "", buf, bufsz);
	104	close(fd);
	105	return ret;
	106	}
	107
cc720ddb	108	static int handle_close(FsContext ctx, V9fsFidOpenState fs)
5f542225	109	{
cc720ddb	110	return close(fs->fd);
5f542225 AK	111	}
5f542225 AK	112
cc720ddb	113	static int handle_closedir(FsContext ctx, V9fsFidOpenState fs)
5f542225	114	{
f314ea4e	115	return closedir(fs->dir.stream);
5f542225 AK	116	}
5f542225 AK	117
cc720ddb AK	118	static int handle_open(FsContext ctx, V9fsPath fs_path,
cc720ddb AK	119	int flags, V9fsFidOpenState *fs)
5f542225 AK	120	{
	121	struct handle_data data = (struct handle_data )ctx->private;
	122
cc720ddb AK	123	fs->fd = open_by_handle(data->mountfd, fs_path->data, flags);
cc720ddb AK	124	return fs->fd;
5f542225 AK	125	}
5f542225 AK	126
cc720ddb AK	127	static int handle_opendir(FsContext *ctx,
cc720ddb AK	128	V9fsPath fs_path, V9fsFidOpenState fs)
5f542225	129	{
cc720ddb AK	130	int ret;
	131	ret = handle_open(ctx, fs_path, O_DIRECTORY, fs);
	132	if (ret < 0) {
	133	return -1;
5f542225	134	}
f314ea4e GK	135	fs->dir.stream = fdopendir(ret);
f314ea4e GK	136	if (!fs->dir.stream) {
cc720ddb AK	137	return -1;
	138	}
	139	return 0;
5f542225 AK	140	}
5f542225 AK	141
cc720ddb	142	static void handle_rewinddir(FsContext ctx, V9fsFidOpenState fs)
5f542225	143	{
f314ea4e	144	rewinddir(fs->dir.stream);
5f542225 AK	145	}
5f542225 AK	146
cc720ddb	147	static off_t handle_telldir(FsContext ctx, V9fsFidOpenState fs)
5f542225	148	{
f314ea4e	149	return telldir(fs->dir.stream);
5f542225 AK	150	}
5f542225 AK	151
635324e8	152	static struct dirent handle_readdir(FsContext ctx, V9fsFidOpenState *fs)
5f542225	153	{
635324e8	154	return readdir(fs->dir.stream);
5f542225 AK	155	}
5f542225 AK	156
cc720ddb	157	static void handle_seekdir(FsContext ctx, V9fsFidOpenState fs, off_t off)
5f542225	158	{
f314ea4e	159	seekdir(fs->dir.stream, off);
5f542225 AK	160	}
5f542225 AK	161
cc720ddb AK	162	static ssize_t handle_preadv(FsContext ctx, V9fsFidOpenState fs,
cc720ddb AK	163	const struct iovec *iov,
5f542225 AK	164	int iovcnt, off_t offset)
	165	{
	166	#ifdef CONFIG_PREADV
cc720ddb	167	return preadv(fs->fd, iov, iovcnt, offset);
5f542225	168	#else
cc720ddb	169	int err = lseek(fs->fd, offset, SEEK_SET);
5f542225 AK	170	if (err == -1) {
	171	return err;
	172	} else {
cc720ddb	173	return readv(fs->fd, iov, iovcnt);
5f542225 AK	174	}
	175	#endif
	176	}
	177
cc720ddb AK	178	static ssize_t handle_pwritev(FsContext ctx, V9fsFidOpenState fs,
cc720ddb AK	179	const struct iovec *iov,
5f542225 AK	180	int iovcnt, off_t offset)
5f542225 AK	181	{
d3ab98e6	182	ssize_t ret;
5f542225	183	#ifdef CONFIG_PREADV
cc720ddb	184	ret = pwritev(fs->fd, iov, iovcnt, offset);
5f542225	185	#else
cc720ddb	186	int err = lseek(fs->fd, offset, SEEK_SET);
5f542225 AK	187	if (err == -1) {
	188	return err;
	189	} else {
cc720ddb	190	ret = writev(fs->fd, iov, iovcnt);
5f542225 AK	191	}
5f542225 AK	192	#endif
d3ab98e6 AK	193	#ifdef CONFIG_SYNC_FILE_RANGE
	194	if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
	195	/*
	196	* Initiate a writeback. This is not a data integrity sync.
	197	* We want to ensure that we don't leave dirty pages in the cache
	198	* after write when writeout=immediate is sepcified.
	199	*/
cc720ddb	200	sync_file_range(fs->fd, offset, ret,
d3ab98e6 AK	201	SYNC_FILE_RANGE_WAIT_BEFORE \| SYNC_FILE_RANGE_WRITE);
	202	}
	203	#endif
	204	return ret;
5f542225 AK	205	}
	206
	207	static int handle_chmod(FsContext fs_ctx, V9fsPath fs_path, FsCred *credp)
	208	{
	209	int fd, ret;
	210	struct handle_data data = (struct handle_data )fs_ctx->private;
	211
	212	fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
	213	if (fd < 0) {
	214	return fd;
	215	}
	216	ret = fchmod(fd, credp->fc_mode);
	217	close(fd);
	218	return ret;
	219	}
	220
	221	static int handle_mknod(FsContext fs_ctx, V9fsPath dir_path,
	222	const char name, FsCred credp)
	223	{
	224	int dirfd, ret;
	225	struct handle_data data = (struct handle_data )fs_ctx->private;
	226
	227	dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
	228	if (dirfd < 0) {
	229	return dirfd;
	230	}
	231	ret = mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev);
	232	if (!ret) {
	233	ret = handle_update_file_cred(dirfd, name, credp);
	234	}
	235	close(dirfd);
	236	return ret;
	237	}
	238
	239	static int handle_mkdir(FsContext fs_ctx, V9fsPath dir_path,
	240	const char name, FsCred credp)
	241	{
	242	int dirfd, ret;
	243	struct handle_data data = (struct handle_data )fs_ctx->private;
	244
	245	dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
	246	if (dirfd < 0) {
	247	return dirfd;
	248	}
	249	ret = mkdirat(dirfd, name, credp->fc_mode);
	250	if (!ret) {
	251	ret = handle_update_file_cred(dirfd, name, credp);
	252	}
	253	close(dirfd);
	254	return ret;
	255	}
	256
8b888272 AK	257	static int handle_fstat(FsContext *fs_ctx, int fid_type,
8b888272 AK	258	V9fsFidOpenState fs, struct stat stbuf)
5f542225	259	{
8b888272 AK	260	int fd;
	261
	262	if (fid_type == P9_FID_DIR) {
f314ea4e	263	fd = dirfd(fs->dir.stream);
8b888272 AK	264	} else {
	265	fd = fs->fd;
	266	}
	267	return fstat(fd, stbuf);
5f542225 AK	268	}
	269
	270	static int handle_open2(FsContext fs_ctx, V9fsPath dir_path, const char *name,
cc720ddb	271	int flags, FsCred credp, V9fsFidOpenState fs)
5f542225 AK	272	{
	273	int ret;
	274	int dirfd, fd;
	275	struct handle_data data = (struct handle_data )fs_ctx->private;
	276
	277	dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
	278	if (dirfd < 0) {
	279	return dirfd;
	280	}
	281	fd = openat(dirfd, name, flags \| O_NOFOLLOW, credp->fc_mode);
	282	if (fd >= 0) {
	283	ret = handle_update_file_cred(dirfd, name, credp);
	284	if (ret < 0) {
	285	close(fd);
	286	fd = ret;
cc720ddb AK	287	} else {
cc720ddb AK	288	fs->fd = fd;
5f542225 AK	289	}
	290	}
	291	close(dirfd);
	292	return fd;
	293	}
	294
	295
	296	static int handle_symlink(FsContext fs_ctx, const char oldpath,
	297	V9fsPath dir_path, const char name, FsCred *credp)
	298	{
	299	int fd, dirfd, ret;
	300	struct handle_data data = (struct handle_data )fs_ctx->private;
	301
	302	dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
	303	if (dirfd < 0) {
	304	return dirfd;
	305	}
	306	ret = symlinkat(oldpath, dirfd, name);
	307	if (!ret) {
	308	fd = openat(dirfd, name, O_PATH \| O_NOFOLLOW);
	309	if (fd < 0) {
	310	ret = fd;
	311	goto err_out;
	312	}
	313	ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
	314	close(fd);
	315	}
	316	err_out:
	317	close(dirfd);
	318	return ret;
	319	}
	320
	321	static int handle_link(FsContext ctx, V9fsPath oldpath,
	322	V9fsPath dirpath, const char name)
	323	{
	324	int oldfd, newdirfd, ret;
	325	struct handle_data data = (struct handle_data )ctx->private;
	326
	327	oldfd = open_by_handle(data->mountfd, oldpath->data, O_PATH);
	328	if (oldfd < 0) {
	329	return oldfd;
	330	}
	331	newdirfd = open_by_handle(data->mountfd, dirpath->data, O_PATH);
	332	if (newdirfd < 0) {
	333	close(oldfd);
	334	return newdirfd;
	335	}
	336	ret = linkat(oldfd, "", newdirfd, name, AT_EMPTY_PATH);
	337	close(newdirfd);
	338	close(oldfd);
	339	return ret;
	340	}
	341
	342	static int handle_truncate(FsContext ctx, V9fsPath fs_path, off_t size)
	343	{
	344	int fd, ret;
	345	struct handle_data data = (struct handle_data )ctx->private;
	346
	347	fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK \| O_WRONLY);
	348	if (fd < 0) {
	349	return fd;
	350	}
	351	ret = ftruncate(fd, size);
	352	close(fd);
353	return ret;
354	}
355
356	static int handle_rename(FsContext ctx, const char oldpath,
357	const char *newpath)
358	{
359	errno = EOPNOTSUPP;
360	return -1;
361	}
362
363	static int handle_chown(FsContext fs_ctx, V9fsPath fs_path, FsCred *credp)
364	{
365	int fd, ret;
366	struct handle_data data = (struct handle_data )fs_ctx->private;
367
368	fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
369	if (fd < 0) {
370	return fd;
371	}
372	ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
373	close(fd);
374	return ret;
375	}
376
377	static int handle_utimensat(FsContext ctx, V9fsPath fs_path,
378	const struct timespec *buf)
379	{
d2042378 AK	380	int ret;
	381	#ifdef CONFIG_UTIMENSAT
	382	int fd;
5f542225 AK	383	struct handle_data data = (struct handle_data )ctx->private;
	384
	385	fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
	386	if (fd < 0) {
	387	return fd;
	388	}
	389	ret = futimens(fd, buf);
	390	close(fd);
d2042378 AK	391	#else
	392	ret = -1;
	393	errno = ENOSYS;
	394	#endif
5f542225 AK	395	return ret;
	396	}
	397
	398	static int handle_remove(FsContext ctx, const char path)
	399	{
	400	errno = EOPNOTSUPP;
	401	return -1;
	402	}
	403
8b888272 AK	404	static int handle_fsync(FsContext *ctx, int fid_type,
8b888272 AK	405	V9fsFidOpenState *fs, int datasync)
5f542225	406	{
8b888272 AK	407	int fd;
	408
	409	if (fid_type == P9_FID_DIR) {
f314ea4e	410	fd = dirfd(fs->dir.stream);
8b888272 AK	411	} else {
	412	fd = fs->fd;
	413	}
	414
5f542225	415	if (datasync) {
8b888272	416	return qemu_fdatasync(fd);
5f542225	417	} else {
8b888272	418	return fsync(fd);
5f542225 AK	419	}
	420	}
	421
	422	static int handle_statfs(FsContext ctx, V9fsPath fs_path,
	423	struct statfs *stbuf)
	424	{
	425	int fd, ret;
	426	struct handle_data data = (struct handle_data )ctx->private;
	427
	428	fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
	429	if (fd < 0) {
	430	return fd;
	431	}
	432	ret = fstatfs(fd, stbuf);
	433	close(fd);
	434	return ret;
	435	}
	436
	437	static ssize_t handle_lgetxattr(FsContext ctx, V9fsPath fs_path,
	438	const char name, void value, size_t size)
	439	{
	440	int fd, ret;
	441	struct handle_data data = (struct handle_data )ctx->private;
	442
	443	fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
	444	if (fd < 0) {
	445	return fd;
	446	}
	447	ret = fgetxattr(fd, name, value, size);
	448	close(fd);
	449	return ret;
	450	}
	451
	452	static ssize_t handle_llistxattr(FsContext ctx, V9fsPath fs_path,
	453	void *value, size_t size)
	454	{
	455	int fd, ret;
	456	struct handle_data data = (struct handle_data )ctx->private;
	457
	458	fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
	459	if (fd < 0) {
	460	return fd;
	461	}
	462	ret = flistxattr(fd, value, size);
	463	close(fd);
	464	return ret;
	465	}
	466
	467	static int handle_lsetxattr(FsContext ctx, V9fsPath fs_path, const char *name,
	468	void *value, size_t size, int flags)
	469	{
	470	int fd, ret;
	471	struct handle_data data = (struct handle_data )ctx->private;
	472
	473	fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
	474	if (fd < 0) {
	475	return fd;
	476	}
	477	ret = fsetxattr(fd, name, value, size, flags);
	478	close(fd);
	479	return ret;
	480	}
	481
	482	static int handle_lremovexattr(FsContext ctx, V9fsPath fs_path,
483	const char *name)
484	{
485	int fd, ret;
486	struct handle_data data = (struct handle_data )ctx->private;
487
488	fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
489	if (fd < 0) {
490	return fd;
491	}
492	ret = fremovexattr(fd, name);
493	close(fd);
494	return ret;
495	}
496
497	static int handle_name_to_path(FsContext ctx, V9fsPath dir_path,
498	const char name, V9fsPath target)
499	{
4fa4ce71	500	char *buffer;
5f542225 AK	501	struct file_handle *fh;
	502	int dirfd, ret, mnt_id;
	503	struct handle_data data = (struct handle_data )ctx->private;
	504
	505	/* "." and ".." are not allowed */
	506	if (!strcmp(name, ".") \|\| !strcmp(name, "..")) {
	507	errno = EINVAL;
	508	return -1;
	509
	510	}
	511	if (dir_path) {
	512	dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
	513	} else {
	514	/* relative to export root */
4fa4ce71 CG	515	buffer = rpath(ctx, ".");
	516	dirfd = open(buffer, O_DIRECTORY);
	517	g_free(buffer);
5f542225 AK	518	}
	519	if (dirfd < 0) {
	520	return dirfd;
	521	}
	522	fh = g_malloc(sizeof(struct file_handle) + data->handle_bytes);
	523	fh->handle_bytes = data->handle_bytes;
66a0a2cb	524	/* add a "./" at the beginning of the path */
4fa4ce71	525	buffer = g_strdup_printf("./%s", name);
5f542225 AK	526	/* flag = 0 imply don't follow symlink */
	527	ret = name_to_handle(dirfd, buffer, fh, &mnt_id, 0);
	528	if (!ret) {
	529	target->data = (char *)fh;
	530	target->size = sizeof(struct file_handle) + data->handle_bytes;
	531	} else {
	532	g_free(fh);
	533	}
	534	close(dirfd);
4fa4ce71	535	g_free(buffer);
5f542225 AK	536	return ret;
	537	}
	538
	539	static int handle_renameat(FsContext ctx, V9fsPath olddir,
	540	const char old_name, V9fsPath newdir,
	541	const char *new_name)
	542	{
	543	int olddirfd, newdirfd, ret;
	544	struct handle_data data = (struct handle_data )ctx->private;
	545
	546	olddirfd = open_by_handle(data->mountfd, olddir->data, O_PATH);
	547	if (olddirfd < 0) {
	548	return olddirfd;
	549	}
	550	newdirfd = open_by_handle(data->mountfd, newdir->data, O_PATH);
	551	if (newdirfd < 0) {
	552	close(olddirfd);
	553	return newdirfd;
	554	}
	555	ret = renameat(olddirfd, old_name, newdirfd, new_name);
	556	close(newdirfd);
	557	close(olddirfd);
	558	return ret;
	559	}
	560
	561	static int handle_unlinkat(FsContext ctx, V9fsPath dir,
	562	const char *name, int flags)
	563	{
	564	int dirfd, ret;
	565	struct handle_data data = (struct handle_data )ctx->private;
930b5883	566	int rflags;
5f542225 AK	567
	568	dirfd = open_by_handle(data->mountfd, dir->data, O_PATH);
	569	if (dirfd < 0) {
	570	return dirfd;
	571	}
	572
930b5883 PB	573	rflags = 0;
	574	if (flags & P9_DOTL_AT_REMOVEDIR) {
	575	rflags \|= AT_REMOVEDIR;
	576	}
	577
	578	ret = unlinkat(dirfd, name, rflags);
	579
5f542225 AK	580	close(dirfd);
	581	return ret;
	582	}
	583
edb9eb73 HPB	584	static int handle_ioc_getversion(FsContext ctx, V9fsPath path,
	585	mode_t st_mode, uint64_t *st_gen)
	586	{
b9317661	587	#ifdef FS_IOC_GETVERSION
cc720ddb AK	588	int err;
cc720ddb AK	589	V9fsFidOpenState fid_open;
edb9eb73 HPB	590
	591	/*
	592	* Do not try to open special files like device nodes, fifos etc
	593	* We can get fd for regular files and directories only
	594	*/
	595	if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
1a9978a5 KS	596	errno = ENOTTY;
1a9978a5 KS	597	return -1;
edb9eb73	598	}
cc720ddb AK	599	err = handle_open(ctx, path, O_RDONLY, &fid_open);
	600	if (err < 0) {
	601	return err;
edb9eb73	602	}
cc720ddb AK	603	err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
cc720ddb AK	604	handle_close(ctx, &fid_open);
edb9eb73	605	return err;
b9317661 KS	606	#else
	607	errno = ENOTTY;
	608	return -1;
	609	#endif
edb9eb73 HPB	610	}
edb9eb73 HPB	611
5f542225 AK	612	static int handle_init(FsContext *ctx)
	613	{
	614	int ret, mnt_id;
edb9eb73	615	struct statfs stbuf;
5f542225 AK	616	struct file_handle fh;
5f542225 AK	617	struct handle_data *data = g_malloc(sizeof(struct handle_data));
d2042378	618
5f542225 AK	619	data->mountfd = open(ctx->fs_root, O_DIRECTORY);
	620	if (data->mountfd < 0) {
	621	ret = data->mountfd;
	622	goto err_out;
	623	}
edb9eb73 HPB	624	ret = statfs(ctx->fs_root, &stbuf);
	625	if (!ret) {
	626	switch (stbuf.f_type) {
	627	case EXT2_SUPER_MAGIC:
	628	case BTRFS_SUPER_MAGIC:
	629	case REISERFS_SUPER_MAGIC:
	630	case XFS_SUPER_MAGIC:
	631	ctx->exops.get_st_gen = handle_ioc_getversion;
	632	break;
	633	}
	634	}
5f542225 AK	635	memset(&fh, 0, sizeof(struct file_handle));
	636	ret = name_to_handle(data->mountfd, ".", &fh, &mnt_id, 0);
	637	if (ret && errno == EOVERFLOW) {
	638	data->handle_bytes = fh.handle_bytes;
	639	ctx->private = data;
	640	ret = 0;
	641	goto out;
	642	}
	643	/* we got 0 byte handle ? */
	644	ret = -1;
	645	close(data->mountfd);
	646	err_out:
	647	g_free(data);
	648	out:
	649	return ret;
	650	}
	651
971f406b LQ	652	static void handle_cleanup(FsContext *ctx)
	653	{
	654	struct handle_data *data = ctx->private;
	655
	656	close(data->mountfd);
	657	g_free(data);
	658	}
	659
99519f0a AK	660	static int handle_parse_opts(QemuOpts opts, struct FsDriverEntry fse)
	661	{
	662	const char *sec_model = qemu_opt_get(opts, "security_model");
	663	const char *path = qemu_opt_get(opts, "path");
	664
	665	if (sec_model) {
63325b18	666	error_report("Invalid argument security_model specified with handle fsdriver");
99519f0a AK	667	return -1;
	668	}
	669
	670	if (!path) {
63325b18	671	error_report("fsdev: No path specified");
99519f0a AK	672	return -1;
	673	}
	674	fse->path = g_strdup(path);
	675	return 0;
	676
	677	}
	678
5f542225	679	FileOperations handle_ops = {
99519f0a	680	.parse_opts = handle_parse_opts,
5f542225	681	.init = handle_init,
971f406b	682	.cleanup = handle_cleanup,
5f542225 AK	683	.lstat = handle_lstat,
	684	.readlink = handle_readlink,
	685	.close = handle_close,
	686	.closedir = handle_closedir,
	687	.open = handle_open,
	688	.opendir = handle_opendir,
	689	.rewinddir = handle_rewinddir,
	690	.telldir = handle_telldir,
635324e8	691	.readdir = handle_readdir,
5f542225 AK	692	.seekdir = handle_seekdir,
	693	.preadv = handle_preadv,
	694	.pwritev = handle_pwritev,
	695	.chmod = handle_chmod,
	696	.mknod = handle_mknod,
	697	.mkdir = handle_mkdir,
	698	.fstat = handle_fstat,
	699	.open2 = handle_open2,
	700	.symlink = handle_symlink,
	701	.link = handle_link,
	702	.truncate = handle_truncate,
	703	.rename = handle_rename,
	704	.chown = handle_chown,
	705	.utimensat = handle_utimensat,
	706	.remove = handle_remove,
	707	.fsync = handle_fsync,
	708	.statfs = handle_statfs,
	709	.lgetxattr = handle_lgetxattr,
	710	.llistxattr = handle_llistxattr,
	711	.lsetxattr = handle_lsetxattr,
	712	.lremovexattr = handle_lremovexattr,
	713	.name_to_path = handle_name_to_path,
	714	.renameat = handle_renameat,
	715	.unlinkat = handle_unlinkat,
	716	};