Re: [Qemu-devel] [PATCH] hw/9pfs: Add CephFS support in VirtFS

[Jevon Qiao <scaleqiao@gmail.com>]

Any further comment on this patch?

Thanks,
Jevon
On 2/3/16 23:41, Jevon Qiao wrote:
> Ceph as a promising unified distributed storage system is widely used in the
> world of OpenStack. OpenStack users deploying Ceph for block (Cinder) and
> object (S3/Swift) are unsurprisingly looking at Manila and CephFS to round out
> a unified storage solution. Since the typical hypervisor people are using is
> Qemu/KVM, it is necessary to provide a high performance, easy to use, file
> system service in it. VirtFS aims to offers paravirtualized system services and
> simple passthrough for directories from host to guest, which currently only
> support local file system, this patch wants to add CephFS support in VirtFS.
>
> Signed-off-by: Jevon Qiao <scaleqiao@gmail.com>
> ---
>   configure                         |  33 ++
>   fsdev/qemu-fsdev.c                |   1 +
>   fsdev/qemu-fsdev.h                |   3 +-
>   hw/9pfs/9p-cephfs.c               | 739 ++++++++++++++++++++++++++++++++++++++
>   hw/9pfs/Makefile.objs             |   3 +
>   scripts/analyse-9p-simpletrace.py |  96 +++++
>   trace-events                      |  33 ++
>   7 files changed, 907 insertions(+), 1 deletion(-)
>   create mode 100644 hw/9pfs/9p-cephfs.c
>
> diff --git a/configure b/configure
> index 0c0472a..a2627be 100755
> --- a/configure
> +++ b/configure
> @@ -275,6 +275,7 @@ trace_backends="log"
>   trace_file="trace"
>   spice=""
>   rbd=""
> +cephfs=""
>   smartcard=""
>   libusb=""
>   usb_redir=""
> @@ -1019,6 +1020,10 @@ for opt do
>     ;;
>     --enable-rbd) rbd="yes"
>     ;;
> +  --disable-cephfs) cephfs="no"
> +  ;;
> +  --enable-cephfs) cephfs="yes"
> +  ;;
>     --disable-xfsctl) xfs="no"
>     ;;
>     --enable-xfsctl) xfs="yes"
> @@ -1345,6 +1350,7 @@ disabled with --disable-FEATURE, default is enabled if available:
>     vhost-net       vhost-net acceleration support
>     spice           spice
>     rbd             rados block device (rbd)
> +  cephfs          Ceph File System
>     libiscsi        iscsi support
>     libnfs          nfs support
>     smartcard       smartcard support (libcacard)
> @@ -3087,6 +3093,28 @@ EOF
>   fi
>   
>   ##########################################
> +# cephfs probe
> +if test "$cephfs" != "no" ; then
> +  cat > $TMPC <<EOF
> +#include <stdio.h>
> +#include <cephfs/libcephfs.h>
> +int main(void) {
> +    struct ceph_mount_info *cmount;
> +    ceph_create(&cmount, NULL);
> +    return 0;
> +}
> +EOF
> +  cephfs_libs="-lcephfs -lrados"
> +  if compile_prog "" "$cephfs_libs" ; then
> +    cephfs=yes
> +  else
> +    if test "$cephfs" = "yes" ; then
> +      feature_not_found "cephfs" "Install libcephfs/ceph devel"
> +    fi
> +    cephfs=no
> +  fi
> +fi
> +##########################################
>   # libssh2 probe
>   min_libssh2_version=1.2.8
>   if test "$libssh2" != "no" ; then
> @@ -4760,6 +4788,7 @@ else
>   echo "spice support     $spice"
>   fi
>   echo "rbd support       $rbd"
> +echo "cephfs support    $cephfs"
>   echo "xfsctl support    $xfs"
>   echo "smartcard support $smartcard"
>   echo "libusb            $libusb"
> @@ -5224,6 +5253,10 @@ if test "$rbd" = "yes" ; then
>     echo "RBD_CFLAGS=$rbd_cflags" >> $config_host_mak
>     echo "RBD_LIBS=$rbd_libs" >> $config_host_mak
>   fi
> +if test "$cephfs" = "yes" ; then
> +  echo "CONFIG_CEPHFS=m" >> $config_host_mak
> +  echo "CEPHFS_LIBS=$cephfs_libs" >> $config_host_mak
> +fi
>   
>   echo "CONFIG_COROUTINE_BACKEND=$coroutine" >> $config_host_mak
>   if test "$coroutine_pool" = "yes" ; then
> diff --git a/fsdev/qemu-fsdev.c b/fsdev/qemu-fsdev.c
> index bf7f0b0..7f07a2a 100644
> --- a/fsdev/qemu-fsdev.c
> +++ b/fsdev/qemu-fsdev.c
> @@ -27,6 +27,7 @@ static FsDriverTable FsDrivers[] = {
>   #endif
>       { .name = "synth", .ops = &synth_ops},
>       { .name = "proxy", .ops = &proxy_ops},
> +    { .name = "cephfs", .ops = &cephfs_ops},
>   };
>   
>   int qemu_fsdev_add(QemuOpts *opts)
> diff --git a/fsdev/qemu-fsdev.h b/fsdev/qemu-fsdev.h
> index 9fa45bf..86a17b8 100644
> --- a/fsdev/qemu-fsdev.h
> +++ b/fsdev/qemu-fsdev.h
> @@ -22,7 +22,7 @@
>    * fstype | ops
>    * -----------------
>    *  local | local_ops
> - *  .     |
> + *  cephfs| cephfs_ops
>    *  .     |
>    *  .     |
>    *  .     |
> @@ -45,4 +45,5 @@ extern FileOperations local_ops;
>   extern FileOperations handle_ops;
>   extern FileOperations synth_ops;
>   extern FileOperations proxy_ops;
> +extern FileOperations cephfs_ops;
>   #endif
> diff --git a/hw/9pfs/9p-cephfs.c b/hw/9pfs/9p-cephfs.c
> new file mode 100644
> index 0000000..f18ec89
> --- /dev/null
> +++ b/hw/9pfs/9p-cephfs.c
> @@ -0,0 +1,739 @@
> +/*
> + * Virtio 9p cephfs callback
> + *
> + * Copyright UnitedStack, Corp. 2016
> + *
> + * Authors:
> + *    Jevon Qiao <scaleqiao@gmail.com>
> + *
> + * 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 "qemu/iov.h"
> +#include "9p.h"
> +#include "9p-xattr.h"
> +#include "trace.h"
> +#include <cephfs/libcephfs.h>
> +#include "fsdev/qemu-fsdev.h"   /* cephfs_ops */
> +#include <arpa/inet.h>
> +#include <pwd.h>
> +#include <grp.h>
> +#include <sys/socket.h>
> +#include <sys/un.h>
> +#include "qemu/xattr.h"
> +#include "qemu/error-report.h"
> +#include <libgen.h>
> +#include <unistd.h>
> +#include <linux/fs.h>
> +#ifdef CONFIG_LINUX_MAGIC_H
> +#include <linux/magic.h>
> +#endif
> +#include <sys/ioctl.h>
> +
> +#define CEPH_VER_LEN        32
> +#define MON_NAME_LEN        32
> +#define MON_SECRET_LEN      64
> +
> +#ifndef LIBCEPHFS_VERSION
> +#define LIBCEPHFS_VERSION(maj, min, extra) ((maj << 16) + (min << 8) + extra)
> +#define LIBCEPHFS_VERSION_CODE LIBCEPHFS_VERSION(0, 0, 0)
> +#endif
> +
> +struct cephfs_data {
> +    int	major, minor, patch;
> +    char ceph_version[CEPH_VER_LEN];
> +    struct  ceph_mount_info *cmount;
> +};
> +
> +/*
> + * Helper function for cephfs_preadv and cephfs_pwritev
> + */
> +inline static ssize_t preadv_pwritev(struct ceph_mount_info *cmount, int fd,
> +                              	    const struct iovec *iov, int iov_cnt,
> +                              	    off_t offset, bool do_write)
> +{
> +    ssize_t ret = 0;
> +    size_t i = 0;
> +    size_t len = 0;
> +    void *buf, *buftmp;
> +    size_t bufoffset = 0;
> +
> +    len = iov_size(iov, iov_cnt);
> +    buf = g_new0(uint8_t, len);
> +    buftmp = buf;
> +    if (do_write) {
> +        for (i = 0; i < iov_cnt; i++) {
> +            memcpy((buftmp + bufoffset), iov[i].iov_base, iov[i].iov_len);
> +            bufoffset += iov[i].iov_len;
> +        }
> +        ret = ceph_write(cmount, fd, buf, len, offset);
> +        if (ret <= 0) {
> +           errno = -ret;
> +           ret = -1;
> +        }
> +    } else {
> +        ret = ceph_read(cmount, fd, buf, len, offset);
> +        if (ret <= 0) {
> +            errno = -ret;
> +            ret = -1;
> +        } else {
> +            for (i = 0; i < iov_cnt; i++) {
> +                memcpy(iov[i].iov_base, (buftmp + bufoffset), iov[i].iov_len);
> +                bufoffset += iov[i].iov_len;
> +            }
> +        }
> +    }
> +
> +    free(buf);
> +    return ret;
> +}
> +
> +static int cephfs_update_file_cred(struct ceph_mount_info *cmount,
> +				   const char *name, FsCred *credp)
> +{
> +    int fd, ret;
> +    fd = ceph_open(cmount, name, O_NONBLOCK | O_NOFOLLOW, credp->fc_mode);
> +    if (fd < 0) {
> +        return fd;
> +    }
> +    ret = ceph_fchown(cmount, fd, credp->fc_uid, credp->fc_gid);
> +    if (ret < 0) {
> +        goto err_out;
> +    }
> +    ret = ceph_fchmod(cmount, fd, credp->fc_mode & 07777);
> +err_out:
> +    close(fd);
> +    return ret;
> +}
> +
> +static int cephfs_lstat(FsContext *fs_ctx, V9fsPath *fs_path,
> +                        struct stat *stbuf)
> +{
> +    int ret;
> +    char *path = fs_path->data;
> +    struct cephfs_data *cfsdata = fs_ctx->private;
> +
> +    ret = ceph_lstat(cfsdata->cmount, path, stbuf);
> +    trace_cephfs_lstat_return(path, stbuf->st_mode, stbuf->st_uid, stbuf->st_gid, stbuf->st_size, ret);
> +    if (ret){
> +        errno = -ret;
> +        ret = -1;
> +    }
> +    return ret;
> +}
> +
> +static ssize_t cephfs_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
> +                               char *buf, size_t bufsz)
> +{
> +    int ret;
> +    char *path = fs_path->data;
> +    struct cephfs_data *cfsdata = fs_ctx->private;
> +
> +    ret = ceph_readlink(cfsdata->cmount, path, buf, bufsz);
> +    trace_cephfs_readlink_return(path, ret);
> +    return ret;
> +}
> +
> +static int cephfs_close(FsContext *ctx, V9fsFidOpenState *fs)
> +{
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    return ceph_close(cfsdata->cmount, fs->fd);
> +}
> +
> +static int cephfs_closedir(FsContext *ctx, V9fsFidOpenState *fs)
> +{
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    return ceph_closedir(cfsdata->cmount, (struct ceph_dir_result *)fs->dir);
> +}
> +
> +static int cephfs_open(FsContext *ctx, V9fsPath *fs_path,
> +                       int flags, V9fsFidOpenState *fs)
> +{
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    fs->fd = ceph_open(cfsdata->cmount, fs_path->data, flags, 0777);
> +    trace_cephfs_open_return(fs_path->data, flags, 0777, fs->fd);
> +    return fs->fd;
> +}
> +
> +static int cephfs_opendir(FsContext *ctx,
> +                          V9fsPath *fs_path, V9fsFidOpenState *fs)
> +{
> +    int ret;
> +    struct ceph_dir_result *result;
> +    struct cephfs_data *cfsdata = ctx->private;
> +    char *path = fs_path->data;
> +
> +    ret = ceph_opendir(cfsdata->cmount, path, &result);
> +    trace_cephfs_opendir_return(path, ret);
> +    if (ret) {
> +        fprintf(stderr, "ceph_opendir=%d\n", ret);
> +        return ret;
> +    }
> +    fs->dir = (DIR *)result;
> +    if (!fs->dir) {
> +        fprintf(stderr, "ceph_opendir return NULL for ceph_dir_result\n");
> +        return -1;
> +    }
> +    return 0;
> +}
> +
> +static void cephfs_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
> +{
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    trace_cephfs_rewinddir(fs->dir);
> +    return ceph_rewinddir(cfsdata->cmount, (struct ceph_dir_result *)fs->dir);
> +}
> +
> +static off_t cephfs_telldir(FsContext *ctx, V9fsFidOpenState *fs)
> +{
> +    int ret;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    trace_cephfs_telldir(fs->dir);
> +    ret = ceph_telldir(cfsdata->cmount, (struct ceph_dir_result *)fs->dir);
> +    return ret;
> +}
> +
> +static int cephfs_readdir_r(FsContext *ctx, V9fsFidOpenState *fs,
> +                            struct dirent *entry,
> +                            struct dirent **result)
> +{
> +    int ret;
> +    struct dirent *tmpent;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    tmpent = entry;
> +    ret = ceph_readdir_r(cfsdata->cmount, (struct ceph_dir_result *)fs->dir,
> +		    	entry);
> +    trace_cephfs_readdir_r_return(tmpent, entry, ret);
> +    if (ret > 0 && entry != NULL)
> +    {
> +        *result = entry;
> +    } else if (!ret)
> +    {
> +        *result = NULL;
> +        entry = tmpent;
> +    }
> +
> +    return ret;
> +}
> +
> +static void cephfs_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
> +{
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    trace_cephfs_seekdir(fs->dir, off);
> +    return ceph_seekdir(cfsdata->cmount, (struct ceph_dir_result*)fs->dir, off);
> +}
> +
> +static ssize_t cephfs_preadv(FsContext *ctx, V9fsFidOpenState *fs,
> +                             const struct iovec *iov,
> +                             int iovcnt, off_t offset)
> +{
> +    ssize_t ret = 0;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    trace_cephfs_preadv(iovcnt, iov_size(iov, iovcnt));
> +#if defined(LIBCEPHFS_VERSION) && LIBCEPHFS_VERSION_CODE >= LIBCEPHFS_VERSION(9, 0, 3)
> +    ret = ceph_preadv(cfsdata->cmount, fs->fd, iov, iovcnt, offset);
> +#else
> +    if (iovcnt > 1) {
> +	ret = preadv_pwritev(cfsdata->cmount, fs->fd, iov, iovcnt, offset, 0);
> +    } else if (iovcnt > 0) {
> +	ret = ceph_read(cfsdata->cmount, fs->fd, iov[0].iov_base,
> +			iov[0].iov_len, offset);
> +    }
> +#endif
> +    trace_cephfs_preadv_return(iovcnt, iov_size(iov, iovcnt), ret);
> +
> +    return ret;
> +}
> +
> +static ssize_t cephfs_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
> +                              const struct iovec *iov,
> +                              int iovcnt, off_t offset)
> +{
> +    ssize_t ret = 0;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    trace_cephfs_pwritev(iovcnt, iov_size(iov, iovcnt), offset);
> +#if defined(LIBCEPHFS_VERSION) && LIBCEPHFS_VERSION_CODE >= LIBCEPHFS_VERSION(9, 0, 3)
> +    ret = ceph_pwritev(cfsdata->cmount, fs->fd, iov, iovcnt, offset);
> +#else
> +    if (iovcnt > 1) {
> +	ret = preadv_pwritev(cfsdata->cmount, fs->fd, iov, iovcnt, offset, 1);
> +    } else if (iovcnt > 0) {
> +	ret = ceph_write(cfsdata->cmount, fs->fd, iov[0].iov_base,
> +			iov[0].iov_len, offset);
> +    }
> +#endif
> +    trace_cephfs_pwritev_return(iovcnt, iov_size(iov, iovcnt), offset, ret);
> +
> +#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 cephfs_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
> +{
> +    int  ret = -1;
> +    struct cephfs_data *cfsdata = fs_ctx->private;
> +
> +    ret = ceph_chmod(cfsdata->cmount, fs_path->data, credp->fc_mode);
> +    trace_cephfs_chmod_return(fs_path->data, credp->fc_mode, ret);
> +    return ret;
> +}
> +
> +static int cephfs_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
> +                       const char *name, FsCred *credp)
> +{
> +    int ret;
> +    V9fsString fullname;
> +    struct cephfs_data *cfsdata = fs_ctx->private;
> +
> +    v9fs_string_init(&fullname);
> +    v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
> +    ret = ceph_mknod(cfsdata->cmount, fullname.data, credp->fc_mode,
> +		    credp->fc_rdev);
> +    trace_cephfs_mknod_return(fullname.data, credp->fc_mode, credp->fc_rdev, ret);
> +
> +    v9fs_string_free(&fullname);
> +    return ret;
> +}
> +
> +static int cephfs_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
> +                       const char *name, FsCred *credp)
> +{
> +    int ret;
> +    V9fsString fullname;
> +    struct cephfs_data *cfsdata = fs_ctx->private;
> +
> +    v9fs_string_init(&fullname);
> +    v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
> +    ret = ceph_mkdir(cfsdata->cmount, fullname.data, credp->fc_mode);
> +    trace_cephfs_mkdir_return(fullname.data, credp->fc_mode, ret);
> +
> +    v9fs_string_free(&fullname);
> +    return ret;
> +}
> +
> +static int cephfs_fstat(FsContext *fs_ctx, int fid_type,
> +                        V9fsFidOpenState *fs, struct stat *stbuf)
> +{
> +    int fd = -1;
> +    int ret;
> +    struct cephfs_data *cfsdata = fs_ctx->private;
> +
> +    if (fid_type == P9_FID_DIR) {
> +        fd = dirfd(fs->dir);
> +    } else {
> +        fd = fs->fd;
> +    }
> +    ret = ceph_fstat(cfsdata->cmount, fd, stbuf);
> +    trace_cephfs_fstat_return(fid_type, fd, stbuf->st_uid, stbuf->st_gid, stbuf->st_size, ret);
> +
> +    return ret;
> +}
> +
> +static int cephfs_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
> +                        int flags, FsCred *credp, V9fsFidOpenState *fs)
> +{
> +    int fd = -1, ret = -1;
> +    V9fsString fullname;
> +    struct cephfs_data *cfsdata = fs_ctx->private;
> +
> +    v9fs_string_init(&fullname);
> +    v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
> +    fd = ceph_open(cfsdata->cmount, fullname.data, flags, credp->fc_mode);
> +    trace_cephfs_open2_return(fullname.data, flags, credp->fc_mode);
> +    if (fd >= 0) {
> +        /* After creating the file, need to set the cred */
> +        ret = cephfs_update_file_cred(cfsdata->cmount, name, credp);
> +        if (ret < 0) {
> +            ceph_close(cfsdata->cmount, fd);
> +            errno = -ret;
> +            fd = ret;
> +        } else {
> +            fs->fd = fd;
> +        }
> +    } else {
> +       errno = -fd;
> +    }
> +
> +    v9fs_string_free(&fullname);
> +    return fd;
> +}
> +
> +static int cephfs_symlink(FsContext *fs_ctx, const char *oldpath,
> +                          V9fsPath *dir_path, const char *name, FsCred *credp)
> +{
> +    int ret = -1;
> +    V9fsString fullname;
> +    struct cephfs_data *cfsdata = fs_ctx->private;
> +
> +    v9fs_string_init(&fullname);
> +    v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
> +    ret = ceph_symlink(cfsdata->cmount, oldpath, fullname.data);
> +    trace_cephfs_symlink_return(oldpath, fullname.data, ret);
> +
> +    v9fs_string_free(&fullname);
> +    return ret;
> +}
> +
> +static int cephfs_link(FsContext *ctx, V9fsPath *oldpath,
> +                       V9fsPath *dirpath, const char *name)
> +{
> +    int ret = -1;
> +    V9fsString newpath;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    v9fs_string_init(&newpath);
> +    v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
> +    ret = ceph_link(cfsdata->cmount, oldpath->data, newpath.data);
> +    trace_cephfs_link_return(oldpath->data, newpath.data, ret);
> +
> +    v9fs_string_free(&newpath);
> +    return ret;
> +}
> +
> +static int cephfs_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
> +{
> +    int ret = -1;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    ret = ceph_truncate(cfsdata->cmount, fs_path->data, size);
> +    trace_cephfs_truncate_return(fs_path->data, size, ret);
> +
> +    return ret;
> +}
> +
> +static int cephfs_rename(FsContext *ctx, const char *oldpath,
> +                         const char *newpath)
> +{
> +    int ret = -1;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    ret = ceph_rename(cfsdata->cmount, oldpath, newpath);
> +    trace_cephfs_rename_return(oldpath, newpath, ret);
> +
> +    return ret;
> +}
> +
> +static int cephfs_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
> +{
> +    int ret = -1;
> +    struct cephfs_data *cfsdata = fs_ctx->private;
> +
> +    ret = ceph_chown(cfsdata->cmount, fs_path->data, credp->fc_uid,
> +		    credp->fc_gid);
> +    trace_cephfs_chown_return(fs_path->data, credp->fc_uid, credp->fc_gid, ret);
> +
> +    return ret;
> +}
> +
> +static int cephfs_utimensat(FsContext *ctx, V9fsPath *fs_path,
> +                            const struct timespec *buf)
> +{
> +    int ret = -1;
> +
> +#ifdef CONFIG_UTIMENSAT
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    ret = ceph_utime(cfsdata->cmount, fs_path->data, (struct utimbuf *)buf);
> +    trace_cephfs_utimensat_return(fs_path->data, ret);
> +#else
> +    ret = -1;
> +    errno = ENOSYS;
> +#endif
> +
> +    return ret;
> +}
> +
> +static int cephfs_remove(FsContext *ctx, const char *path)
> +{
> +    errno = EOPNOTSUPP;
> +    return -1;
> +}
> +
> +static int cephfs_fsync(FsContext *ctx, int fid_type,
> +                        V9fsFidOpenState *fs, int datasync)
> +{
> +    int ret = -1, fd = -1;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    if (fid_type == P9_FID_DIR) {
> +        fd = dirfd(fs->dir);
> +    } else {
> +        fd = fs->fd;
> +    }
> +    ret = ceph_fsync(cfsdata->cmount, fd, datasync);
> +    trace_cephfs_fsync_return(fd, datasync, ret);
> +
> +    return ret;
> +}
> +
> +static int cephfs_statfs(FsContext *ctx, V9fsPath *fs_path,
> +                         struct statfs *stbuf)
> +{
> +    int ret;
> +    char *path = fs_path->data;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    ret = ceph_statfs(cfsdata->cmount, path, (struct statvfs*)stbuf);
> +    if (ret) {
> +        fprintf(stderr, "ceph_statfs=%d\n", ret);
> +    }
> +
> +    return ret;
> +}
> +
> +/*
> + * Get the extended attribute of normal file, if the path refer to a symbolic
> + * link, just return the extended attributes of the syslink rather than the
> + * attributes of the link itself.
> + */
> +static ssize_t cephfs_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
> +                                const char *name, void *value, size_t size)
> +{
> +    int ret;
> +    char *path = fs_path->data;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    ret = ceph_lgetxattr(cfsdata->cmount, path, name, value, size);
> +    trace_cephfs_lgetxattr_return(path, name, ret);
> +
> +    return ret;
> +}
> +
> +static ssize_t cephfs_llistxattr(FsContext *ctx, V9fsPath *fs_path,
> +                                 void *value, size_t size)
> +{
> +    int ret = -1;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    ret = ceph_llistxattr(cfsdata->cmount, fs_path->data, value, size);
> +    trace_cephfs_llistxattr_return(fs_path->data, ret);
> +
> +    return ret;
> +}
> +
> +static int cephfs_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
> +                            void *value, size_t size, int flags)
> +{
> +    int ret = -1;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    ret = ceph_lsetxattr(cfsdata->cmount, fs_path->data, name, value, size,
> +	flags);
> +    trace_cephfs_lsetxattr_return(fs_path->data, name, flags, ret);
> +
> +    return ret;
> +}
> +
> +static int cephfs_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
> +                               const char *name)
> +{
> +    int ret = -1;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    ret = ceph_lremovexattr(cfsdata->cmount, fs_path->data, name);
> +    trace_cephfs_lremovexattr_return(fs_path->data, name, ret);
> +
> +    return ret;
> +}
> +
> +static int cephfs_name_to_path(FsContext *ctx, V9fsPath *dir_path,
> +                              const char *name, V9fsPath *target)
> +{
> +    if (dir_path) {
> +        v9fs_string_sprintf((V9fsString *)target, "%s/%s",
> +                            dir_path->data, name);
> +    } else {
> +        /* if the path does not start from '/' */
> +        v9fs_string_sprintf((V9fsString *)target, "%s", name);
> +    }
> +
> +    /* Bump the size for including terminating NULL */
> +    target->size++;
> +    return 0;
> +}
> +
> +static int cephfs_renameat(FsContext *ctx, V9fsPath *olddir,
> +                           const char *old_name, V9fsPath *newdir,
> +                           const char *new_name)
> +{
> +    int ret = -1;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    ret = ceph_rename(cfsdata->cmount, old_name, new_name);
> +    trace_cephfs_renameat_return(old_name, new_name, ret);
> +
> +    return ret;
> +}
> +
> +static int cephfs_unlinkat(FsContext *ctx, V9fsPath *dir,
> +                           const char *name, int flags)
> +{
> +    int ret = 0;
> +    char *path = dir->data;
> +    struct stat fstat;
> +    V9fsString fullname;
> +    struct cephfs_data *cfsdata = ctx->private;
> +
> +    v9fs_string_init(&fullname);
> +    v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name);
> +    path = fullname.data;
> +    /* determine which kind of file is being destroyed */
> +    ret = ceph_lstat(cfsdata->cmount, path, &fstat);
> +    if (!ret) {
> +        switch (fstat.st_mode & S_IFMT) {
> +        case S_IFDIR:
> +            ret = ceph_rmdir(cfsdata->cmount, path);
> +            break;
> +
> +        case S_IFBLK:
> +        case S_IFCHR:
> +        case S_IFIFO:
> +        case S_IFLNK:
> +        case S_IFREG:
> +        case S_IFSOCK:
> +            ret = ceph_unlink(cfsdata->cmount, path);
> +            break;
> +
> +        default:
> +            fprintf(stderr, "ceph_lstat unknown stmode\n");
> +            break;
> +        }
> +    } else {
> +        errno = -ret;
> +        ret = -1;
> +    }
> +    trace_cephfs_unlinkat_return(path, fstat.st_mode, ret);
> +
> +    v9fs_string_free(&fullname);
> +    return ret;
> +}
> +
> +/*
> + * Do two things in the init function:
> + * 1) Create a mount handle used by all cephfs interfaces.
> + * 2) Invoke ceph_mount() to initialize a link between the client and
> + *    ceph monitor
> + */
> +static int cephfs_init(FsContext *ctx)
> +{
> +    int ret;
> +    const char *ver = NULL;
> +    struct cephfs_data *data = g_malloc(sizeof(struct cephfs_data));
> +
> +    if (data == NULL) {
> +	errno = ENOMEM;
> +	return -1;
> +    }
> +    trace_cephfs_init(ctx->fs_root);
> +    memset(data, 0, sizeof(struct cephfs_data));
> +    ret = ceph_create(&data->cmount, NULL);
> +    if (ret) {
> +        fprintf(stderr, "ceph_create=%d\n", ret);
> +        goto err_out;
> +    }
> +
> +    ret = ceph_conf_read_file(data->cmount, NULL);
> +    if (ret) {
> +        fprintf(stderr, "ceph_conf_read_file=%d\n", ret);
> +        goto err_out;
> +    }
> +
> +    ret = ceph_mount(data->cmount, ctx->fs_root);
> +    if (ret) {
> +        fprintf(stderr, "ceph_mount=%d\n", ret);
> +        goto err_out;
> +    } else {
> +        ctx->private = data;
> +	/* CephFS does not support FS_IOC_GETVERSIO */
> +	ctx->exops.get_st_gen = NULL;
> +        goto out;
> +    }
> +
> +    ver = ceph_version(&data->major, &data->minor, &data->patch);
> +    memcpy(data->ceph_version, ver, strlen(ver) + 1);
> +
> +err_out:
> +    g_free(data);
> +out:
> +    return ret;
> +}
> +
> +static int cephfs_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) {
> +        fprintf(stderr, "Invalid argument security_model specified with "
> +		"cephfs fsdriver\n");
> +        return -1;
> +    }
> +
> +    if (!path) {
> +        fprintf(stderr, "fsdev: No path specified.\n");
> +        return -1;
> +    }
> +
> +    fse->path = g_strdup(path);
> +    return 0;
> +}
> +
> +FileOperations cephfs_ops = {
> +    .parse_opts   = cephfs_parse_opts,
> +    .init         = cephfs_init,
> +    .lstat        = cephfs_lstat,
> +    .readlink     = cephfs_readlink,
> +    .close        = cephfs_close,
> +    .closedir     = cephfs_closedir,
> +    .open         = cephfs_open,
> +    .opendir      = cephfs_opendir,
> +    .rewinddir    = cephfs_rewinddir,
> +    .telldir      = cephfs_telldir,
> +    .readdir_r    = cephfs_readdir_r,
> +    .seekdir      = cephfs_seekdir,
> +    .preadv       = cephfs_preadv,
> +    .pwritev      = cephfs_pwritev,
> +    .chmod        = cephfs_chmod,
> +    .mknod        = cephfs_mknod,
> +    .mkdir        = cephfs_mkdir,
> +    .fstat        = cephfs_fstat,
> +    .open2        = cephfs_open2,
> +    .symlink      = cephfs_symlink,
> +    .link         = cephfs_link,
> +    .truncate     = cephfs_truncate,
> +    .rename       = cephfs_rename,
> +    .chown        = cephfs_chown,
> +    .utimensat    = cephfs_utimensat,
> +    .remove       = cephfs_remove,
> +    .fsync        = cephfs_fsync,
> +    .statfs       = cephfs_statfs,
> +    .lgetxattr    = cephfs_lgetxattr,
> +    .llistxattr   = cephfs_llistxattr,
> +    .lsetxattr    = cephfs_lsetxattr,
> +    .lremovexattr = cephfs_lremovexattr,
> +    .name_to_path = cephfs_name_to_path,
> +    .renameat     = cephfs_renameat,
> +    .unlinkat     = cephfs_unlinkat,
> +};
> diff --git a/hw/9pfs/Makefile.objs b/hw/9pfs/Makefile.objs
> index da0ae0c..a77a6f4 100644
> --- a/hw/9pfs/Makefile.objs
> +++ b/hw/9pfs/Makefile.objs
> @@ -5,5 +5,8 @@ common-obj-y += coth.o cofs.o codir.o cofile.o
>   common-obj-y += coxattr.o 9p-synth.o
>   common-obj-$(CONFIG_OPEN_BY_HANDLE) +=  9p-handle.o
>   common-obj-y += 9p-proxy.o
> +common-obj-y += 9p-cephfs.o
>   
>   obj-y += virtio-9p-device.o
> +
> +9p-cephfs.o-libs := $(CEPHFS_LIBS)
> diff --git a/scripts/analyse-9p-simpletrace.py b/scripts/analyse-9p-simpletrace.py
> index 3c3dee4..fe0a496 100755
> --- a/scripts/analyse-9p-simpletrace.py
> +++ b/scripts/analyse-9p-simpletrace.py
> @@ -210,4 +210,100 @@ class VirtFSRequestTracker(simpletrace.Analyzer):
>           def v9fs_readlink_return(self, tag, id, target):
>                   print "RREADLINK (tag =", tag, ", target =", target, ")"
>   
> +	def cephfs_lstat_return(self, path, stmode, stuid, stgid, stsize, ret):
> +		print "RCEPHFSLSTAT (path =", path, ", stmode =", stmode, ", stuid =", stuid, ", stgid =", stgid, ", stsize =", stsize, ", ret =", ret, ")"
> +
> +	def cephfs_readlink_return(self, path, ret):
> +		print "RCEPHFSREADLINK (path =", path, ", ret =", ret, ")"
> +
> +	def cephfs_open_return(self, path, flags, mode, fd):
> +		print "RCEPHFSOPEN (path =", path, ", flags =", flags, ", mode =", mode, ", fd =", fd, ")"
> +
> +	def cephfs_opendir_return(self, path, ret):
> +		print "RCEPHFSOPENDIR (path =", path, ", ret =", ret, ")"
> +
> +	def cephfs_rewinddir(self, dir):
> +		print "TCEPHFSREWINDDIR (dir =", dir, ")"
> +
> +	def cephfs_telldir(self, dir):
> +		print "TCEPHFSTELLDIR (dir =", dir, ")"
> +
> +	def cephfs_readdir_r_return(self, tmpent, entry, ret):
> +		print "RCEPHFSREADDIRR (tmpent =", tmpent, ", entry =", entry, ", ret =", ret, ")"
> +
> +	def cephfs_seekdir(self, dir, off):
> +		print "TCEPHFSSEEKDIR (dir =", dir, ", off =", off, ")"
> +
> +	def cephfs_preadv(self, iovcnt, len):
> +		print "TCEPHFSPREADV (iovcnt=", iovcnt, ", len =", len, ")"
> +
> +	def cephfs_preadv_return(self, iovcnt, len, ret):
> +		print "RCEPHFSPREADV (iovcnt=", iovcnt, ", len =", len, ", ret = ", ret, ")"
> +
> +	def cephfs_pwritev(self, iovcnt, len, offset):
> +		print "TCEPHFSPWRITEV (iovcnt=", iovcnt, ", len =", len, ", offset =", offset, ")"
> +
> +	def cephfs_pwritev_return(self, iovcnt, len, offset, ret):
> +		print "RCEPHFSPWRITEV (iovcnt=", iovcnt, ", len =", len, ", offset =", offset, ", ret = ", ret, ")"
> +
> +	def cephfs_chmod(self, path, fcmode):
> +		print "TCEPHFSCHMOD (path =", path, ", fcmode =", fcmode, ")"
> +
> +	def cephfs_chmod_return(self, path, fcmode, ret):
> +		print "RCEPHFSCHMOD (path =", path, ", fcmode =", fcmode, ", ret =", ret, ")"
> +
> +	def cephfs_mknod_return(self, path, fcmode, fcrdev, ret):
> +		print "RCEPHFSMKNOD (path =", path, ", fcmode =", fcmode, ", fcrdev =", fcrdev, ", ret =", ret, ")"
> +
> +	def cephfs_mkdir_return(self, path, fcmode, ret):
> +		print "RCEPHFSMKDIR (path =", path, ", fcmode =", fcmode, ", ret =", ret, ")"
> +
> +	def cephfs_fstat_return(self, fidtype, fd, stuid, stgid, stsize, ret):
> +		print "RCEPHFSFSTAT (fidtype =", fidtype, ", fd =", fd, ", stuid =", stuid, ", stgid =", stgid, ", stsize =", stsize, ", ret =", ret, ")"
> +
> +	def cephfs_open2_return(self, path, flags, fcmode):
> +		print "RCEPHFSOPEN2 (path =", path, ", flags =", flags, "fcmode =", fcmode, ")"
> +
> +	def cephfs_symlink_return(self, oldpath, path, ret):
> +		print "RCEPHFSSYMLINK (oldpath =", oldpath, ", path =", path, ", ret =", ret, ")"
> +
> +	def cephfs_link_return(self, oldpath, path, ret):
> +		print "RCEPHFSLINK (oldpath =", oldpath, ", path =", path, ", ret =", ret, ")"
> +
> +	def cephfs_truncate_return(self, path, size, ret):
> +		print "RCEPHFSTRUNCATE (path =", path, ", size =", size, ", ret =", ret, ")"
> +
> +	def cephfs_rename_return(self, oldpath, newpath, ret):
> +		print "RCEPHFSRENAME (oldpath =", oldpath, ", newpath =", newpath, ", ret =", ret, ")"
> +
> +	def cephfs_chown_return(self, path, fcuid, fcgid, ret):
> +		print "RCEPHFSCHOWN (path =", path, ", fcuid =", fcuid, ", fcgid =", fcgid, ", ret =", ret, ")"
> +
> +	def cephfs_utimensat_return(self, path, ret):
> +		print "RCEPHFSUTIMENSAT (path =", path, ", ret =", ret, ")"
> +
> +	def cephfs_fsync_return(self, fd, datasync, ret):
> +		print "RCEPHFSFSYNC (fd =", fd, ", datasync =", datasync, ", ret =", ret, ")"
> +
> +	def cephfs_lgetxattr_return(self, path, name, ret):
> +		print "RCEPHFSLGETXATTR (path =", path, ", name =", name, ", ret =", ret, ")"
> +
> +	def cephfs_llistxattr_return(self, path, ret):
> +		print "RCEPHFSLLISTXATTR (path =", path, ", ret =", ret, ")"
> +
> +	def cephfs_lsetxattr_return(self, path, name, flags, ret):
> +		print "RCEPHFSLSETXATTR (path =", path, ", name =", name, ", flags =", flags, ", ret =", ret, ")"
> +
> +	def cephfs_lremovexattr_return(self, path, name, ret):
> +		print "RCEPHFSLREMOVEXATTR (path =", path, ", name =", name, ", ret =", ret, ")"
> +
> +	def cephfs_renameat_return(self, oldname, newname, ret):
> +		print "RCEPHFSRENAMEAT (oldname =", oldname, ", newname =", newname, ", ret =", ret, ")"
> +
> +	def cephfs_unlinkat_return(self, path, stmode, ret):
> +		print "RCEPHFSUNLINKAT (path =", path, ", stmode =", stmode, ", ret =", ret, ")"
> +
> +	def cephfs_init(self, path):
> +		print "RCEPHFSINIT (path =", path, ")"
> +
>   simpletrace.run(VirtFSRequestTracker())
> diff --git a/trace-events b/trace-events
> index 6fba6cc..11879d2 100644
> --- a/trace-events
> +++ b/trace-events
> @@ -1118,6 +1118,39 @@ v9fs_xattrcreate(uint16_t tag, uint8_t id, int32_t fid, char* name, int64_t size
>   v9fs_readlink(uint16_t tag, uint8_t id, int32_t fid) "tag %d id %d fid %d"
>   v9fs_readlink_return(uint16_t tag, uint8_t id, char* target) "tag %d id %d name %s"
>   
> +# hw/9pfs/9p-cephfs.c
> +cephfs_lstat_return(char *path, int stmode, int stuid, int stgid, int stsize, int ret) "path %s stmode %d stuid %d stgid %d stsize %d ret %d"
> +cephfs_readlink_return(char *path, int ret) "path %s ret %d"
> +cephfs_open_return(char *path, int flags, int mode, int fd) "path %s flags %d mode %d fd %d"
> +cephfs_opendir_return(char *path, int ret) "path %s ret %d"
> +cephfs_rewinddir(void *dir) "dir %p"
> +cephfs_telldir(void *dir) "dir %p"
> +cephfs_readdir_r_return(void *tmpent, void *entry, int ret) "tmpent %p entry %p ret %d"
> +cephfs_seekdir(void *dir, int off) "dir %p off %d"
> +cephfs_preadv(int iovcnt, int len) "iovcnt %d len %d"
> +cephfs_preadv_return(int iovcnt, int len, long ret) "iovcnt %d len %d ret %l"
> +cephfs_pwritev(int iovcnt, int len, int offset) "iovcnt %d len %d offset %d"
> +cephfs_pwritev_return(int iovcnt, int len, int offset, long ret) "iovcnt %d len %d offset %d ret %l"cephfs_chmod(char *path, int fcmode) "path %s fcmode %d"
> +cephfs_chmod_return(char *path, int fcmode, int ret) "path %s fcmode %d ret %d"
> +cephfs_mknod_return(char *path, int fcmode, uint32_t fcrdev, int ret) "path %s fcmode %d fcrdev %u ret %d"
> +cephfs_mkdir_return(char *path, int fcmode, int ret) " path %s fcmode %d ret %d"
> +cephfs_fstat_return(int fidtype, int fd, int stuid, int stgid, int stsize, int ret) "fidtype %d fd %d stuid %d stgid %d stsize %d ret %d"
> +cephfs_open2_return(char *path, int flags, int fcmode) "path %s flags %d fcmode %d"
> +cephfs_symlink_return(const char *oldpath, char *path, int ret) "oldpath %s path %s ret %d"
> +cephfs_link_return(char *oldpath, char *path, int ret) "oldpath %s path %s ret %d"
> +cephfs_truncate_return(char *path, int size, int ret) "path %s size %d ret %d"
> +cephfs_rename_return(const char *oldpath, const char *newpath, int ret) "oldpath %s newpath %s ret %d"
> +cephfs_chown_return(char *path, int fcuid, int fcgid, int ret) "path %s fcuid %d fcgid %d ret %d"
> +cephfs_utimensat_return(char *path, int ret) "path %s ret %d"
> +cephfs_fsync_return(int fd, int datasync, int ret) "fd %d datasync %d ret %d"
> +cephfs_lgetxattr_return(char *path, const char *name, int ret) "path %s name %s ret %d"
> +cephfs_llistxattr_return(char *path, int ret) "path %s ret %d"
> +cephfs_lsetxattr_return(char *path, const char *name, int flags, int ret) "path %s name %s flags %d ret %d"
> +cephfs_lremovexattr_return(char *path, const char *name, int ret) "path %s name %s ret %d"
> +cephfs_renameat_return(const char *oldname, const char *newname, int ret) "oldname %s newname %s ret %d"
> +cephfs_unlinkat_return(char *path, int stmode, int ret) "path %s stmode %d ret %d"
> +cephfs_init(char *path) "path %s"
> +
>   # target-sparc/mmu_helper.c
>   mmu_helper_dfault(uint64_t address, uint64_t context, int mmu_idx, uint32_t tl) "DFAULT at %"PRIx64" context %"PRIx64" mmu_idx=%d tl=%d"
>   mmu_helper_dprot(uint64_t address, uint64_t context, int mmu_idx, uint32_t tl) "DPROT at %"PRIx64" context %"PRIx64" mmu_idx=%d tl=%d"