Merge remote-tracking branch 'aneesh/for-upstream' into staging

* aneesh/for-upstream:
  hw/9pfs: Remove O_NOATIME flag from 9pfs open() calls in readonly mode
  hw/9pfs: Update MAINTAINERS file
  fsdev: Fix parameter parsing for proxy helper
  hw/9pfs: Fix crash when mounting with synthfs
  hw/9pfs: Preserve S_ISGID
  hw/9pfs: Add new security model mapped-file.

5 files changed, 367 insertions, 20 deletions

diff --git a/hw/9pfs/cofile.c b/hw/9pfs/cofile.c
index b15838c..9345aae 100644
--- a/hw/9pfs/cofile.c
+++ b/hw/9pfs/cofile.c
@@ -76,6 +76,20 @@ int v9fs_co_fstat(V9fsPDU *pdu, V9fsFidState *fidp, struct stat *stbuf)
                 err = -errno;
             }
         });
+    /*
+     * Some FS driver (local:mapped-file) can't support fetching attributes
+     * using file descriptor. Use Path name in that case.
+     */
+    if (err == -EOPNOTSUPP) {
+        err = v9fs_co_lstat(pdu, &fidp->path, stbuf);
+        if (err == -ENOENT) {
+            /*
+             * fstat on an unlinked file. Work with partial results
+             * returned from s->ops->fstat
+             */
+            err = 0;
+        }
+    }
     return err;
 }
 
diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
index 3f15540..791a557 100644
--- a/hw/9pfs/virtio-9p-device.c
+++ b/hw/9pfs/virtio-9p-device.c
@@ -91,15 +91,6 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf)
         s->ctx.fs_root = NULL;
     }
     s->ctx.exops.get_st_gen = NULL;
-
-    if (fse->export_flags & V9FS_SM_PASSTHROUGH) {
-        s->ctx.xops = passthrough_xattr_ops;
-    } else if (fse->export_flags & V9FS_SM_MAPPED) {
-        s->ctx.xops = mapped_xattr_ops;
-    } else if (fse->export_flags & V9FS_SM_NONE) {
-        s->ctx.xops = none_xattr_ops;
-    }
-
     len = strlen(conf->tag);
     if (len > MAX_TAG_LEN - 1) {
         fprintf(stderr, "mount tag '%s' (%d bytes) is longer than "
diff --git a/hw/9pfs/virtio-9p-handle.c b/hw/9pfs/virtio-9p-handle.c
index cb012c0..f96d17a 100644
--- a/hw/9pfs/virtio-9p-handle.c
+++ b/hw/9pfs/virtio-9p-handle.c
@@ -63,11 +63,11 @@ static int handle_update_file_cred(int dirfd, const char *name, FsCred *credp)
     if (fd < 0) {
         return fd;
     }
-    ret = fchmod(fd, credp->fc_mode & 07777);
+    ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
     if (ret < 0) {
         goto err_out;
     }
-    ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
+    ret = fchmod(fd, credp->fc_mode & 07777);
 err_out:
     close(fd);
     return ret;
diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
index 3ae6ef2..33a41d2 100644
--- a/hw/9pfs/virtio-9p-local.c
+++ b/hw/9pfs/virtio-9p-local.c
@@ -20,6 +20,7 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 #include "qemu-xattr.h"
+#include <libgen.h>
 #include <linux/fs.h>
 #ifdef CONFIG_LINUX_MAGIC_H
 #include <linux/magic.h>
@@ -39,6 +40,54 @@
 #define BTRFS_SUPER_MAGIC 0x9123683E
 #endif
 
+#define VIRTFS_META_DIR ".virtfs_metadata"
+
+static const char *local_mapped_attr_path(FsContext *ctx,
+                                          const char *path, char *buffer)
+{
+    char *dir_name;
+    char *tmp_path = strdup(path);
+    char *base_name = basename(tmp_path);
+
+    /* NULL terminate the directory */
+    dir_name = tmp_path;
+    *(base_name - 1) = '\0';
+
+    snprintf(buffer, PATH_MAX, "%s/%s/%s/%s",
+             ctx->fs_root, dir_name, VIRTFS_META_DIR, base_name);
+    free(tmp_path);
+    return buffer;
+}
+
+#define ATTR_MAX 100
+static void local_mapped_file_attr(FsContext *ctx, const char *path,
+                                   struct stat *stbuf)
+{
+    FILE *fp;
+    char buf[ATTR_MAX];
+    char attr_path[PATH_MAX];
+
+    local_mapped_attr_path(ctx, path, attr_path);
+    fp = fopen(attr_path, "r");
+    if (!fp) {
+        return;
+    }
+    memset(buf, 0, ATTR_MAX);
+    while (fgets(buf, ATTR_MAX, fp)) {
+        if (!strncmp(buf, "virtfs.uid", 10)) {
+            stbuf->st_uid = atoi(buf+11);
+        } else if (!strncmp(buf, "virtfs.gid", 10)) {
+            stbuf->st_gid = atoi(buf+11);
+        } else if (!strncmp(buf, "virtfs.mode", 11)) {
+            stbuf->st_mode = atoi(buf+12);
+        } else if (!strncmp(buf, "virtfs.rdev", 11)) {
+            stbuf->st_rdev = atoi(buf+12);
+        }
+        memset(buf, 0, ATTR_MAX);
+    }
+    fclose(fp);
+}
+
 static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
 {
     int err;
@@ -71,10 +120,103 @@ static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
                         sizeof(dev_t)) > 0) {
                 stbuf->st_rdev = tmp_dev;
         }
+    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        local_mapped_file_attr(fs_ctx, path, stbuf);
     }
     return err;
 }
 
+static int local_create_mapped_attr_dir(FsContext *ctx, const char *path)
+{
+    int err;
+    char attr_dir[PATH_MAX];
+    char *tmp_path = strdup(path);
+
+    snprintf(attr_dir, PATH_MAX, "%s/%s/%s",
+             ctx->fs_root, dirname(tmp_path), VIRTFS_META_DIR);
+
+    err = mkdir(attr_dir, 0700);
+    if (err < 0 && errno == EEXIST) {
+        err = 0;
+    }
+    free(tmp_path);
+    return err;
+}
+
+static int local_set_mapped_file_attr(FsContext *ctx,
+                                      const char *path, FsCred *credp)
+{
+    FILE *fp;
+    int ret = 0;
+    char buf[ATTR_MAX];
+    char attr_path[PATH_MAX];
+    int uid = -1, gid = -1, mode = -1, rdev = -1;
+
+    fp = fopen(local_mapped_attr_path(ctx, path, attr_path), "r");
+    if (!fp) {
+        goto create_map_file;
+    }
+    memset(buf, 0, ATTR_MAX);
+    while (fgets(buf, ATTR_MAX, fp)) {
+        if (!strncmp(buf, "virtfs.uid", 10)) {
+            uid = atoi(buf+11);
+        } else if (!strncmp(buf, "virtfs.gid", 10)) {
+            gid = atoi(buf+11);
+        } else if (!strncmp(buf, "virtfs.mode", 11)) {
+            mode = atoi(buf+12);
+        } else if (!strncmp(buf, "virtfs.rdev", 11)) {
+            rdev = atoi(buf+12);
+        }
+        memset(buf, 0, ATTR_MAX);
+    }
+    fclose(fp);
+    goto update_map_file;
+
+create_map_file:
+    ret = local_create_mapped_attr_dir(ctx, path);
+    if (ret < 0) {
+        goto err_out;
+    }
+
+update_map_file:
+    fp = fopen(attr_path, "w");
+    if (!fp) {
+        ret = -1;
+        goto err_out;
+    }
+
+    if (credp->fc_uid != -1) {
+        uid = credp->fc_uid;
+    }
+    if (credp->fc_gid != -1) {
+        gid = credp->fc_gid;
+    }
+    if (credp->fc_mode != -1) {
+        mode = credp->fc_mode;
+    }
+    if (credp->fc_rdev != -1) {
+        rdev = credp->fc_rdev;
+    }
+
+
+    if (uid != -1) {
+        fprintf(fp, "virtfs.uid=%d\n", uid);
+    }
+    if (gid != -1) {
+        fprintf(fp, "virtfs.gid=%d\n", gid);
+    }
+    if (mode != -1) {
+        fprintf(fp, "virtfs.mode=%d\n", mode);
+    }
+    if (rdev != -1) {
+        fprintf(fp, "virtfs.rdev=%d\n", rdev);
+    }
+    fclose(fp);
+
+err_out:
+    return ret;
+}
+
 static int local_set_xattr(const char *path, FsCred *credp)
 {
     int err;
@@ -115,9 +257,6 @@ static int local_post_create_passthrough(FsContext *fs_ctx, const char *path,
 {
     char buffer[PATH_MAX];
 
-    if (chmod(rpath(fs_ctx, path, buffer), credp->fc_mode & 07777) < 0) {
-        return -1;
-    }
     if (lchown(rpath(fs_ctx, path, buffer), credp->fc_uid,
                 credp->fc_gid) < 0) {
         /*
@@ -128,6 +267,10 @@ static int local_post_create_passthrough(FsContext *fs_ctx, const char *path,
             return -1;
         }
     }
+
+    if (chmod(rpath(fs_ctx, path, buffer), credp->fc_mode & 07777) < 0) {
+        return -1;
+    }
     return 0;
 }
 
@@ -138,7 +281,8 @@ static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
     char buffer[PATH_MAX];
     char *path = fs_path->data;
 
-    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
+    if ((fs_ctx->export_flags & V9FS_SM_MAPPED) ||
+        (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
         int fd;
         fd = open(rpath(fs_ctx, path, buffer), O_RDONLY);
         if (fd == -1) {
@@ -203,7 +347,18 @@ static int local_readdir_r(FsContext *ctx, V9fsFidOpenState *fs,
                            struct dirent *entry,
                            struct dirent **result)
 {
-    return readdir_r(fs->dir, entry, result);
+    int ret;
+
+again:
+    ret = readdir_r(fs->dir, entry, result);
+    if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        if (!ret && *result != NULL &&
+            !strcmp(entry->d_name, VIRTFS_META_DIR)) {
+            /* skp the meta data directory */
+            goto again;
+        }
+    }
+    return ret;
 }
 
 static void local_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
@@ -264,6 +419,8 @@ static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 
     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
         return local_set_xattr(rpath(fs_ctx, path, buffer), credp);
+    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        return local_set_mapped_file_attr(fs_ctx, path, credp);
     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {
         return chmod(rpath(fs_ctx, path, buffer), credp->fc_mode);
@@ -296,6 +453,18 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
             serrno = errno;
             goto err_end;
         }
+    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+
+        err = mknod(rpath(fs_ctx, path, buffer),
+                    SM_LOCAL_MODE_BITS|S_IFREG, 0);
+        if (err == -1) {
+            goto out;
+        }
+        err = local_set_mapped_file_attr(fs_ctx, path, credp);
+        if (err == -1) {
+            serrno = errno;
+            goto err_end;
+        }
     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {
         err = mknod(rpath(fs_ctx, path, buffer), credp->fc_mode,
@@ -344,6 +513,17 @@ static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
             serrno = errno;
             goto err_end;
         }
+    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        err = mkdir(rpath(fs_ctx, path, buffer), SM_LOCAL_DIR_MODE_BITS);
+        if (err == -1) {
+            goto out;
+        }
+        credp->fc_mode = credp->fc_mode|S_IFDIR;
+        err = local_set_mapped_file_attr(fs_ctx, path, credp);
+        if (err == -1) {
+            serrno = errno;
+            goto err_end;
+        }
     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {
         err = mkdir(rpath(fs_ctx, path, buffer), credp->fc_mode);
@@ -404,6 +584,9 @@ static int local_fstat(FsContext *fs_ctx, int fid_type,
                       &tmp_dev, sizeof(dev_t)) > 0) {
                 stbuf->st_rdev = tmp_dev;
         }
+    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        errno = EOPNOTSUPP;
+        return -1;
     }
     return err;
 }
@@ -436,6 +619,19 @@ static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
             serrno = errno;
             goto err_end;
         }
+    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        fd = open(rpath(fs_ctx, path, buffer), flags, SM_LOCAL_MODE_BITS);
+        if (fd == -1) {
+            err = fd;
+            goto out;
+        }
+        credp->fc_mode = credp->fc_mode|S_IFREG;
+        /* Set client credentials in .virtfs_metadata directory files */
+        err = local_set_mapped_file_attr(fs_ctx, path, credp);
+        if (err == -1) {
+            serrno = errno;
+            goto err_end;
+        }
     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {
         fd = open(rpath(fs_ctx, path, buffer), flags, credp->fc_mode);
@@ -506,6 +702,35 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
             serrno = errno;
             goto err_end;
         }
+    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        int fd;
+        ssize_t oldpath_size, write_size;
+        fd = open(rpath(fs_ctx, newpath, buffer), O_CREAT|O_EXCL|O_RDWR,
+                  SM_LOCAL_MODE_BITS);
+        if (fd == -1) {
+            err = fd;
+            goto out;
+        }
+        /* Write the oldpath (target) to the file. */
+        oldpath_size = strlen(oldpath);
+        do {
+            write_size = write(fd, (void *)oldpath, oldpath_size);
+        } while (write_size == -1 && errno == EINTR);
+
+        if (write_size != oldpath_size) {
+            serrno = errno;
+            close(fd);
+            err = -1;
+            goto err_end;
+        }
+        close(fd);
+        /* Set cleint credentials in symlink's xattr */
+        credp->fc_mode = credp->fc_mode|S_IFLNK;
+        err = local_set_mapped_file_attr(fs_ctx, newpath, credp);
+        if (err == -1) {
+            serrno = errno;
+            goto err_end;
+        }
     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {
         err = symlink(oldpath, rpath(fs_ctx, newpath, buffer));
@@ -548,6 +773,21 @@ static int local_link(FsContext *ctx, V9fsPath *oldpath,
 
     ret = link(rpath(ctx, oldpath->data, buffer),
                rpath(ctx, newpath.data, buffer1));
+
+    /* now link the virtfs_metadata files */
+    if (!ret && (ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
+        /* Link the .virtfs_metadata files. Create the metada directory */
+        ret = local_create_mapped_attr_dir(ctx, newpath.data);
+        if (ret < 0) {
+            goto err_out;
+        }
+        ret = link(local_mapped_attr_path(ctx, oldpath->data, buffer),
+                   local_mapped_attr_path(ctx, newpath.data, buffer1));
+        if (ret < 0 && errno != ENOENT) {
+            goto err_out;
+        }
+    }
+err_out:
     v9fs_string_free(&newpath);
     return ret;
 }
@@ -563,8 +803,21 @@ static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
 static int local_rename(FsContext *ctx, const char *oldpath,
                         const char *newpath)
 {
+    int err;
     char buffer[PATH_MAX], buffer1[PATH_MAX];
 
+    if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        err = local_create_mapped_attr_dir(ctx, newpath);
+        if (err < 0) {
+            return err;
+        }
+        /* rename the .virtfs_metadata files */
+        err = rename(local_mapped_attr_path(ctx, oldpath, buffer),
+                     local_mapped_attr_path(ctx, newpath, buffer1));
+        if (err < 0 && errno != ENOENT) {
+            return err;
+        }
+    }
     return rename(rpath(ctx, oldpath, buffer), rpath(ctx, newpath, buffer1));
 }
 
@@ -580,6 +833,8 @@ static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
                       credp->fc_uid, credp->fc_gid);
     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
         return local_set_xattr(rpath(fs_ctx, path, buffer), credp);
+    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        return local_set_mapped_file_attr(fs_ctx, path, credp);
     }
     return -1;
 }
@@ -595,8 +850,46 @@ static int local_utimensat(FsContext *s, V9fsPath *fs_path,
 
 static int local_remove(FsContext *ctx, const char *path)
 {
+    int err;
+    struct stat stbuf;
     char buffer[PATH_MAX];
+
+    if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        err =  lstat(rpath(ctx, path, buffer), &stbuf);
+        if (err) {
+            goto err_out;
+        }
+        /*
+         * If directory remove .virtfs_metadata contained in the
+         * directory
+         */
+        if (S_ISDIR(stbuf.st_mode)) {
+            sprintf(buffer, "%s/%s/%s", ctx->fs_root, path, VIRTFS_META_DIR);
+            err = remove(buffer);
+            if (err < 0 && errno != ENOENT) {
+                /*
+                 * We didn't had the .virtfs_metadata file. May be file created
+                 * in non-mapped mode ?. Ignore ENOENT.
+                 */
+                goto err_out;
+            }
+        }
+        /*
+         * Now remove the name from parent directory
+         * .virtfs_metadata directory
+         */
+        err = remove(local_mapped_attr_path(ctx, path, buffer));;
+        if (err < 0 && errno != ENOENT) {
+            /*
+             * We didn't had the .virtfs_metadata file. May be file created
+             * in non-mapped mode ?. Ignore ENOENT.
+             */
+            goto err_out;
+        }
+    }
     return remove(rpath(ctx, path, buffer));
+err_out:
+    return err;
 }
 
 static int local_fsync(FsContext *ctx, int fid_type,
@@ -696,12 +989,45 @@ static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
     int ret;
     V9fsString fullname;
     char buffer[PATH_MAX];
+
     v9fs_string_init(&fullname);
 
     v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name);
+    if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        if (flags == AT_REMOVEDIR) {
+            /*
+             * If directory remove .virtfs_metadata contained in the
+             * directory
+             */
+            sprintf(buffer, "%s/%s/%s", ctx->fs_root,
+                    fullname.data, VIRTFS_META_DIR);
+            ret = remove(buffer);
+            if (ret < 0 && errno != ENOENT) {
+                /*
+                 * We didn't had the .virtfs_metadata file. May be file created
+                 * in non-mapped mode ?. Ignore ENOENT.
+                 */
+                goto err_out;
+            }
+        }
+        /*
+         * Now remove the name from parent directory
+         * .virtfs_metadata directory.
+         */
+        ret = remove(local_mapped_attr_path(ctx, fullname.data, buffer));
+        if (ret < 0 && errno != ENOENT) {
+            /*
+             * We didn't had the .virtfs_metadata file. May be file created
+             * in non-mapped mode ?. Ignore ENOENT.
+             */
+            goto err_out;
+        }
+    }
+    /* Remove the name finally */
     ret = remove(rpath(ctx, fullname.data, buffer));
     v9fs_string_free(&fullname);
 
+err_out:
     return ret;
 }
 
@@ -736,6 +1062,19 @@ static int local_init(FsContext *ctx)
     int err = 0;
     struct statfs stbuf;
 
+    if (ctx->export_flags & V9FS_SM_PASSTHROUGH) {
+        ctx->xops = passthrough_xattr_ops;
+    } else if (ctx->export_flags & V9FS_SM_MAPPED) {
+        ctx->xops = mapped_xattr_ops;
+    } else if (ctx->export_flags & V9FS_SM_NONE) {
+        ctx->xops = none_xattr_ops;
+    } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        /*
+         * xattr operation for mapped-file and passthrough
+         * remain same.
+         */
+        ctx->xops = passthrough_xattr_ops;
+    }
     ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
 #ifdef FS_IOC_GETVERSION
     /*
@@ -770,13 +1109,17 @@ static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
 
     if (!strcmp(sec_model, "passthrough")) {
         fse->export_flags |= V9FS_SM_PASSTHROUGH;
-    } else if (!strcmp(sec_model, "mapped")) {
+    } else if (!strcmp(sec_model, "mapped") ||
+               !strcmp(sec_model, "mapped-xattr")) {
         fse->export_flags |= V9FS_SM_MAPPED;
     } else if (!strcmp(sec_model, "none")) {
         fse->export_flags |= V9FS_SM_NONE;
+    } else if (!strcmp(sec_model, "mapped-file")) {
+        fse->export_flags |= V9FS_SM_MAPPED_FILE;
     } else {
         fprintf(stderr, "Invalid security model %s specified, valid options are"
-                "\n\t [passthrough|mapped|none]\n", sec_model);
+                "\n\t [passthrough|mapped-xattr|mapped-file|none]\n",
+                sec_model);
         return -1;
     }
 
diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index e6ba6ba..a72ffc3 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -986,7 +986,7 @@ static void v9fs_attach(void *opaque)
     s->root_fid = fid;
     /* disable migration */
     error_set(&s->migration_blocker, QERR_VIRTFS_FEATURE_BLOCKS_MIGRATION,
-              s->ctx.fs_root, s->tag);
+              s->ctx.fs_root ? s->ctx.fs_root : "NULL", s->tag);
     migrate_add_blocker(s->migration_blocker);
 out:
     put_fid(pdu, fidp);
@@ -1391,7 +1391,6 @@ static void v9fs_open(void *opaque)
                 err = -EROFS;
                 goto out;
             }
-            flags |= O_NOATIME;
         }
         err = v9fs_co_open(pdu, fidp, flags);
         if (err < 0) {