Commit f8ad4a89 authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V
Browse files

hw/9pfs: Use little-endian format for xattr values 



With security_model=mapped-xattr, we encode the uid,gid and other file
attributes as extended attributes of the file. We save them under
user.virtfs.* namespace.

Use little-endian encoding for on-disk values. This enables us to export
the same directory from both little-endian and big-endian hosts.

NOTE: This will break big-endian host that have virtFS exports
using security model mapped-xattr. They will have to use external tools
to convert the xattr to little-endian format.

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
parent 30eaca3a

hw/9pfs/virtio-9p-local.c

+20 −24
Original line number Diff line number Diff line
@@ -135,17 +135,17 @@ static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf) 
        mode_t tmp_mode;

        dev_t tmp_dev;

        if (getxattr(buffer, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) {

            stbuf->st_uid = tmp_uid;

            stbuf->st_uid = le32_to_cpu(tmp_uid);

        }

        if (getxattr(buffer, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) {

            stbuf->st_gid = tmp_gid;

            stbuf->st_gid = le32_to_cpu(tmp_gid);

        }

        if (getxattr(buffer, "user.virtfs.mode",

                    &tmp_mode, sizeof(mode_t)) > 0) {

            stbuf->st_mode = tmp_mode;

            stbuf->st_mode = le32_to_cpu(tmp_mode);

        }

        if (getxattr(buffer, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) {

                stbuf->st_rdev = tmp_dev;

            stbuf->st_rdev = le64_to_cpu(tmp_dev);

        }

    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {

        local_mapped_file_attr(fs_ctx, path, stbuf);
@@ -255,29 +255,29 @@ static int local_set_xattr(const char *path, FsCred *credp) 
    int err;



    if (credp->fc_uid != -1) {

        err = setxattr(path, "user.virtfs.uid", &credp->fc_uid, sizeof(uid_t),

                0);

        uint32_t tmp_uid = cpu_to_le32(credp->fc_uid);

        err = setxattr(path, "user.virtfs.uid", &tmp_uid, sizeof(uid_t), 0);

        if (err) {

            return err;

        }

    }

    if (credp->fc_gid != -1) {

        err = setxattr(path, "user.virtfs.gid", &credp->fc_gid, sizeof(gid_t),

                0);

        uint32_t tmp_gid = cpu_to_le32(credp->fc_gid);

        err = setxattr(path, "user.virtfs.gid", &tmp_gid, sizeof(gid_t), 0);

        if (err) {

            return err;

        }

    }

    if (credp->fc_mode != -1) {

        err = setxattr(path, "user.virtfs.mode", &credp->fc_mode,

                sizeof(mode_t), 0);

        uint32_t tmp_mode = cpu_to_le32(credp->fc_mode);

        err = setxattr(path, "user.virtfs.mode", &tmp_mode, sizeof(mode_t), 0);

        if (err) {

            return err;

        }

    }

    if (credp->fc_rdev != -1) {

        err = setxattr(path, "user.virtfs.rdev", &credp->fc_rdev,

                sizeof(dev_t), 0);

        uint64_t tmp_rdev = cpu_to_le64(credp->fc_rdev);

        err = setxattr(path, "user.virtfs.rdev", &tmp_rdev, sizeof(dev_t), 0);

        if (err) {

            return err;

        }
@@ -630,21 +630,17 @@ static int local_fstat(FsContext *fs_ctx, int fid_type, 
        mode_t tmp_mode;

        dev_t tmp_dev;



        if (fgetxattr(fd, "user.virtfs.uid",

                      &tmp_uid, sizeof(uid_t)) > 0) {

            stbuf->st_uid = tmp_uid;

        if (fgetxattr(fd, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) {

            stbuf->st_uid = le32_to_cpu(tmp_uid);

        }

        if (fgetxattr(fd, "user.virtfs.gid",

                      &tmp_gid, sizeof(gid_t)) > 0) {

            stbuf->st_gid = tmp_gid;

        if (fgetxattr(fd, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) {

            stbuf->st_gid = le32_to_cpu(tmp_gid);

        }

        if (fgetxattr(fd, "user.virtfs.mode",

                      &tmp_mode, sizeof(mode_t)) > 0) {

            stbuf->st_mode = tmp_mode;

        if (fgetxattr(fd, "user.virtfs.mode", &tmp_mode, sizeof(mode_t)) > 0) {

            stbuf->st_mode = le32_to_cpu(tmp_mode);

        }

        if (fgetxattr(fd, "user.virtfs.rdev",

                      &tmp_dev, sizeof(dev_t)) > 0) {

                stbuf->st_rdev = tmp_dev;

        if (fgetxattr(fd, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) {

            stbuf->st_rdev = le64_to_cpu(tmp_dev);

        }

    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {

        errno = EOPNOTSUPP;