Merge remote-tracking branch 'mst/tags/for_upstream' into staging

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

diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index bf63eab729ad72c3ff4c6a3d0d8042497f369510..a2486566afb7bfebeffa9d9467ebca3b421e5c9a 100644 (file)
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -11,8 +11,11 @@
  *
  */
 
  *
  */
 

+#include "qemu/osdep.h"

 #include "9p.h"
 #include "9p.h"

+#include "9p-local.h"

 #include "9p-xattr.h"
 #include "9p-xattr.h"

+#include "9p-util.h"

 #include "fsdev/qemu-fsdev.h"   /* local_ops */
 #include <arpa/inet.h>
 #include <pwd.h>
 #include "fsdev/qemu-fsdev.h"   /* local_ops */
 #include <arpa/inet.h>
 #include <pwd.h>


@@ -20,6 +23,8 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 #include "qemu/xattr.h"
 #include <sys/socket.h>
 #include <sys/un.h>
 #include "qemu/xattr.h"

+#include "qemu/cutils.h"
+#include "qemu/error-report.h"

 #include <libgen.h>
 #include <linux/fs.h>
 #ifdef CONFIG_LINUX_MAGIC_H
 #include <libgen.h>
 #include <linux/fs.h>
 #ifdef CONFIG_LINUX_MAGIC_H


@@ -40,40 +45,62 @@
 #define BTRFS_SUPER_MAGIC 0x9123683E
 #endif
 
 #define BTRFS_SUPER_MAGIC 0x9123683E
 #endif
 

-#define VIRTFS_META_DIR ".virtfs_metadata"
+typedef struct {
+    int mountfd;
+} LocalData;

 
 

-static char *local_mapped_attr_path(FsContext *ctx, const char *path)
+int local_open_nofollow(FsContext *fs_ctx, const char *path, int flags,
+                        mode_t mode)

 {
 {

-    int dirlen;
-    const char *name = strrchr(path, '/');
-    if (name) {
-        dirlen = name - path;
-        ++name;
-    } else {
-        name = path;
-        dirlen = 0;
+    LocalData *data = fs_ctx->private;
+
+    /* All paths are relative to the path data->mountfd points to */
+    while (*path == '/') {
+        path++;

     }
     }

-    return g_strdup_printf("%s/%.*s/%s/%s", ctx->fs_root,
-                           dirlen, path, VIRTFS_META_DIR, name);
+
+    return relative_openat_nofollow(data->mountfd, path, flags, mode);
+}
+
+int local_opendir_nofollow(FsContext *fs_ctx, const char *path)
+{
+    return local_open_nofollow(fs_ctx, path, O_DIRECTORY | O_RDONLY, 0);

 }
 
 }
 

-static FILE *local_fopen(const char *path, const char *mode)
+static void renameat_preserve_errno(int odirfd, const char *opath, int ndirfd,
+                                    const char *npath)
+{
+    int serrno = errno;
+    renameat(odirfd, opath, ndirfd, npath);
+    errno = serrno;
+}
+
+static void unlinkat_preserve_errno(int dirfd, const char *path, int flags)
+{
+    int serrno = errno;
+    unlinkat(dirfd, path, flags);
+    errno = serrno;
+}
+
+#define VIRTFS_META_DIR ".virtfs_metadata"
+
+static FILE *local_fopenat(int dirfd, const char *name, const char *mode)

 {
     int fd, o_mode = 0;
     FILE *fp;
 {
     int fd, o_mode = 0;
     FILE *fp;

-    int flags = O_NOFOLLOW;
+    int flags;

     /*
      * only supports two modes
      */
     if (mode[0] == 'r') {
     /*
      * only supports two modes
      */
     if (mode[0] == 'r') {

-        flags |= O_RDONLY;
+        flags = O_RDONLY;

     } else if (mode[0] == 'w') {
     } else if (mode[0] == 'w') {

-        flags |= O_WRONLY | O_TRUNC | O_CREAT;
+        flags = O_WRONLY | O_TRUNC | O_CREAT;

         o_mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
     } else {
         return NULL;
     }
         o_mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
     } else {
         return NULL;
     }

-    fd = open(path, flags, o_mode);
+    fd = openat_file(dirfd, name, flags, o_mode);

     if (fd == -1) {
         return NULL;
     }
     if (fd == -1) {
         return NULL;
     }


@@ -85,16 +112,20 @@ static FILE *local_fopen(const char *path, const char *mode)
 }
 
 #define ATTR_MAX 100
 }
 
 #define ATTR_MAX 100

-static void local_mapped_file_attr(FsContext *ctx, const char *path,
+static void local_mapped_file_attr(int dirfd, const char *name,

                                    struct stat *stbuf)
 {
     FILE *fp;
     char buf[ATTR_MAX];
                                    struct stat *stbuf)
 {
     FILE *fp;
     char buf[ATTR_MAX];

-    char *attr_path;
+    int map_dirfd;
+
+    map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR);
+    if (map_dirfd == -1) {
+        return;
+    }

 
 

-    attr_path = local_mapped_attr_path(ctx, path);
-    fp = local_fopen(attr_path, "r");
-    g_free(attr_path);
+    fp = local_fopenat(map_dirfd, name, "r");
+    close_preserve_errno(map_dirfd);

     if (!fp) {
         return;
     }
     if (!fp) {
         return;
     }


@@ -116,12 +147,17 @@ static void local_mapped_file_attr(FsContext *ctx, const char *path,
 
 static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
 {
 
 static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
 {

-    int err;
-    char *buffer;
-    char *path = fs_path->data;
+    int err = -1;
+    char *dirpath = g_path_get_dirname(fs_path->data);
+    char *name = g_path_get_basename(fs_path->data);
+    int dirfd;
+
+    dirfd = local_opendir_nofollow(fs_ctx, dirpath);
+    if (dirfd == -1) {
+        goto out;
+    }

 
 

-    buffer = rpath(fs_ctx, path);
-    err =  lstat(buffer, stbuf);
+    err = fstatat(dirfd, name, stbuf, AT_SYMLINK_NOFOLLOW);

     if (err) {
         goto err_out;
     }
     if (err) {
         goto err_out;
     }


@@ -131,87 +167,83 @@ static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
         gid_t tmp_gid;
         mode_t tmp_mode;
         dev_t tmp_dev;
         gid_t tmp_gid;
         mode_t tmp_mode;
         dev_t tmp_dev;

-        if (getxattr(buffer, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) {
+
+        if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.uid", &tmp_uid,
+                                 sizeof(uid_t)) > 0) {

             stbuf->st_uid = le32_to_cpu(tmp_uid);
         }
             stbuf->st_uid = le32_to_cpu(tmp_uid);
         }

-        if (getxattr(buffer, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) {
+        if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.gid", &tmp_gid,
+                                 sizeof(gid_t)) > 0) {

             stbuf->st_gid = le32_to_cpu(tmp_gid);
         }
             stbuf->st_gid = le32_to_cpu(tmp_gid);
         }

-        if (getxattr(buffer, "user.virtfs.mode",
-                    &tmp_mode, sizeof(mode_t)) > 0) {
+        if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.mode", &tmp_mode,
+                                 sizeof(mode_t)) > 0) {

             stbuf->st_mode = le32_to_cpu(tmp_mode);
         }
             stbuf->st_mode = le32_to_cpu(tmp_mode);
         }

-        if (getxattr(buffer, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) {
+        if (fgetxattrat_nofollow(dirfd, name, "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) {
             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);
+        local_mapped_file_attr(dirfd, name, stbuf);

     }
 
 err_out:
     }
 
 err_out:

-    g_free(buffer);
-    return err;
-}
-
-static int local_create_mapped_attr_dir(FsContext *ctx, const char *path)
-{
-    int err;
-    char *attr_dir;
-    char *tmp_path = g_strdup(path);
-
-    attr_dir = g_strdup_printf("%s/%s/%s",
-             ctx->fs_root, dirname(tmp_path), VIRTFS_META_DIR);
-
-    err = mkdir(attr_dir, 0700);
-    if (err < 0 && errno == EEXIST) {
-        err = 0;
-    }
-    g_free(attr_dir);
-    g_free(tmp_path);
+    close_preserve_errno(dirfd);
+out:
+    g_free(name);
+    g_free(dirpath);

     return err;
 }
 
     return err;
 }
 

-static int local_set_mapped_file_attr(FsContext *ctx,
-                                      const char *path, FsCred *credp)
+static int local_set_mapped_file_attrat(int dirfd, const char *name,
+                                        FsCred *credp)

 {
     FILE *fp;
 {
     FILE *fp;

-    int ret = 0;
+    int ret;

     char buf[ATTR_MAX];
     char buf[ATTR_MAX];

-    char *attr_path;

     int uid = -1, gid = -1, mode = -1, rdev = -1;
     int uid = -1, gid = -1, mode = -1, rdev = -1;

+    int map_dirfd;
+
+    ret = mkdirat(dirfd, VIRTFS_META_DIR, 0700);
+    if (ret < 0 && errno != EEXIST) {
+        return -1;
+    }
+
+    map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR);
+    if (map_dirfd == -1) {
+        return -1;
+    }

 
 

-    attr_path = local_mapped_attr_path(ctx, path);
-    fp = local_fopen(attr_path, "r");
+    fp = local_fopenat(map_dirfd, name, "r");

     if (!fp) {
     if (!fp) {

-        goto create_map_file;
+        if (errno == ENOENT) {
+            goto update_map_file;
+        } else {
+            close_preserve_errno(map_dirfd);
+            return -1;
+        }

     }
     memset(buf, 0, ATTR_MAX);
     while (fgets(buf, ATTR_MAX, fp)) {
         if (!strncmp(buf, "virtfs.uid", 10)) {
     }
     memset(buf, 0, ATTR_MAX);
     while (fgets(buf, ATTR_MAX, fp)) {
         if (!strncmp(buf, "virtfs.uid", 10)) {

-            uid = atoi(buf+11);
+            uid = atoi(buf + 11);

         } else if (!strncmp(buf, "virtfs.gid", 10)) {
         } else if (!strncmp(buf, "virtfs.gid", 10)) {

-            gid = atoi(buf+11);
+            gid = atoi(buf + 11);

         } else if (!strncmp(buf, "virtfs.mode", 11)) {
         } else if (!strncmp(buf, "virtfs.mode", 11)) {

-            mode = atoi(buf+12);
+            mode = atoi(buf + 12);

         } else if (!strncmp(buf, "virtfs.rdev", 11)) {
         } else if (!strncmp(buf, "virtfs.rdev", 11)) {

-            rdev = atoi(buf+12);
+            rdev = atoi(buf + 12);

         }
         memset(buf, 0, ATTR_MAX);
     }
     fclose(fp);
         }
         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:
 
 update_map_file:

-    fp = local_fopen(attr_path, "w");
+    fp = local_fopenat(map_dirfd, name, "w");
+    close_preserve_errno(map_dirfd);

     if (!fp) {
     if (!fp) {

-        ret = -1;
-        goto err_out;
+        return -1;

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


@@ -227,7 +259,6 @@ update_map_file:
         rdev = credp->fc_rdev;
     }
 
         rdev = credp->fc_rdev;
     }
 

-

     if (uid != -1) {
         fprintf(fp, "virtfs.uid=%d\n", uid);
     }
     if (uid != -1) {
         fprintf(fp, "virtfs.uid=%d\n", uid);
     }


@@ -242,39 +273,71 @@ update_map_file:
     }
     fclose(fp);
 
     }
     fclose(fp);
 

-err_out:
-    g_free(attr_path);
+    return 0;
+}
+
+static int fchmodat_nofollow(int dirfd, const char *name, mode_t mode)
+{
+    int fd, ret;
+
+    /* FIXME: this should be handled with fchmodat(AT_SYMLINK_NOFOLLOW).
+     * Unfortunately, the linux kernel doesn't implement it yet. As an
+     * alternative, let's open the file and use fchmod() instead. This
+     * may fail depending on the permissions of the file, but it is the
+     * best we can do to avoid TOCTTOU. We first try to open read-only
+     * in case name points to a directory. If that fails, we try write-only
+     * in case name doesn't point to a directory.
+     */
+    fd = openat_file(dirfd, name, O_RDONLY, 0);
+    if (fd == -1) {
+        /* In case the file is writable-only and isn't a directory. */
+        if (errno == EACCES) {
+            fd = openat_file(dirfd, name, O_WRONLY, 0);
+        }
+        if (fd == -1 && errno == EISDIR) {
+            errno = EACCES;
+        }
+    }
+    if (fd == -1) {
+        return -1;
+    }
+    ret = fchmod(fd, mode);
+    close_preserve_errno(fd);

     return ret;
 }
 
     return ret;
 }
 

-static int local_set_xattr(const char *path, FsCred *credp)
+static int local_set_xattrat(int dirfd, const char *path, FsCred *credp)

 {
     int err;
 
     if (credp->fc_uid != -1) {
         uint32_t tmp_uid = cpu_to_le32(credp->fc_uid);
 {
     int err;
 
     if (credp->fc_uid != -1) {
         uint32_t tmp_uid = cpu_to_le32(credp->fc_uid);

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

         if (err) {
             return err;
         }
     }
     if (credp->fc_gid != -1) {
         uint32_t tmp_gid = cpu_to_le32(credp->fc_gid);
         if (err) {
             return err;
         }
     }
     if (credp->fc_gid != -1) {
         uint32_t tmp_gid = cpu_to_le32(credp->fc_gid);

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

         if (err) {
             return err;
         }
     }
     if (credp->fc_mode != -1) {
         uint32_t tmp_mode = cpu_to_le32(credp->fc_mode);
         if (err) {
             return err;
         }
     }
     if (credp->fc_mode != -1) {
         uint32_t tmp_mode = cpu_to_le32(credp->fc_mode);

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

         if (err) {
             return err;
         }
     }
     if (credp->fc_rdev != -1) {
         uint64_t tmp_rdev = cpu_to_le64(credp->fc_rdev);
         if (err) {
             return err;
         }
     }
     if (credp->fc_rdev != -1) {
         uint64_t tmp_rdev = cpu_to_le64(credp->fc_rdev);

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

         if (err) {
             return err;
         }
         if (err) {
             return err;
         }


@@ -282,58 +345,56 @@ static int local_set_xattr(const char *path, FsCred *credp)
     return 0;
 }
 
     return 0;
 }
 

-static int local_post_create_passthrough(FsContext *fs_ctx, const char *path,
-                                         FsCred *credp)
+static int local_set_cred_passthrough(FsContext *fs_ctx, int dirfd,
+                                      const char *name, FsCred *credp)

 {
 {

-    char *buffer;
-
-    buffer = rpath(fs_ctx, path);
-    if (lchown(buffer, credp->fc_uid, credp->fc_gid) < 0) {
+    if (fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,
+                 AT_SYMLINK_NOFOLLOW) < 0) {

         /*
          * If we fail to change ownership and if we are
          * using security model none. Ignore the error
          */
         if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
         /*
          * If we fail to change ownership and if we are
          * using security model none. Ignore the error
          */
         if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {

-            goto err;
+            return -1;

         }
     }
 
         }
     }
 

-    if (chmod(buffer, credp->fc_mode & 07777) < 0) {
-        goto err;
-    }
-
-    g_free(buffer);
-    return 0;
-err:
-    g_free(buffer);
-    return -1;
+    return fchmodat_nofollow(dirfd, name, credp->fc_mode & 07777);

 }
 
 static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
                               char *buf, size_t bufsz)
 {
     ssize_t tsize = -1;
 }
 
 static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
                               char *buf, size_t bufsz)
 {
     ssize_t tsize = -1;

-    char *buffer;
-    char *path = fs_path->data;

 
     if ((fs_ctx->export_flags & V9FS_SM_MAPPED) ||
         (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
         int fd;
 
     if ((fs_ctx->export_flags & V9FS_SM_MAPPED) ||
         (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
         int fd;

-        buffer = rpath(fs_ctx, path);
-        fd = open(buffer, O_RDONLY | O_NOFOLLOW);
-        g_free(buffer);
+
+        fd = local_open_nofollow(fs_ctx, fs_path->data, O_RDONLY, 0);

         if (fd == -1) {
             return -1;
         }
         do {
             tsize = read(fd, (void *)buf, bufsz);
         } while (tsize == -1 && errno == EINTR);
         if (fd == -1) {
             return -1;
         }
         do {
             tsize = read(fd, (void *)buf, bufsz);
         } while (tsize == -1 && errno == EINTR);

-        close(fd);
+        close_preserve_errno(fd);

     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {
     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {

-        buffer = rpath(fs_ctx, path);
-        tsize = readlink(buffer, buf, bufsz);
-        g_free(buffer);
+        char *dirpath = g_path_get_dirname(fs_path->data);
+        char *name = g_path_get_basename(fs_path->data);
+        int dirfd;
+
+        dirfd = local_opendir_nofollow(fs_ctx, dirpath);
+        if (dirfd == -1) {
+            goto out;
+        }
+
+        tsize = readlinkat(dirfd, name, buf, bufsz);
+        close_preserve_errno(dirfd);
+    out:
+        g_free(name);
+        g_free(dirpath);

     }
     return tsize;
 }
     }
     return tsize;
 }


@@ -345,70 +406,83 @@ static int local_close(FsContext *ctx, V9fsFidOpenState *fs)
 
 static int local_closedir(FsContext *ctx, V9fsFidOpenState *fs)
 {
 
 static int local_closedir(FsContext *ctx, V9fsFidOpenState *fs)
 {

-    return closedir(fs->dir);
+    return closedir(fs->dir.stream);

 }
 
 static int local_open(FsContext *ctx, V9fsPath *fs_path,
                       int flags, V9fsFidOpenState *fs)
 {
 }
 
 static int local_open(FsContext *ctx, V9fsPath *fs_path,
                       int flags, V9fsFidOpenState *fs)
 {

-    char *buffer;
-    char *path = fs_path->data;
+    int fd;

 
 

-    buffer = rpath(ctx, path);
-    fs->fd = open(buffer, flags | O_NOFOLLOW);
-    g_free(buffer);
+    fd = local_open_nofollow(ctx, fs_path->data, flags, 0);
+    if (fd == -1) {
+        return -1;
+    }
+    fs->fd = fd;

     return fs->fd;
 }
 
 static int local_opendir(FsContext *ctx,
                          V9fsPath *fs_path, V9fsFidOpenState *fs)
 {
     return fs->fd;
 }
 
 static int local_opendir(FsContext *ctx,
                          V9fsPath *fs_path, V9fsFidOpenState *fs)
 {

-    char *buffer;
-    char *path = fs_path->data;
+    int dirfd;
+    DIR *stream;
+
+    dirfd = local_opendir_nofollow(ctx, fs_path->data);
+    if (dirfd == -1) {
+        return -1;
+    }

 
 

-    buffer = rpath(ctx, path);
-    fs->dir = opendir(buffer);
-    g_free(buffer);
-    if (!fs->dir) {
+    stream = fdopendir(dirfd);
+    if (!stream) {
+        close(dirfd);

         return -1;
     }
         return -1;
     }

+    fs->dir.stream = stream;

     return 0;
 }
 
 static void local_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
 {
     return 0;
 }
 
 static void local_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
 {

-    rewinddir(fs->dir);
+    rewinddir(fs->dir.stream);

 }
 
 static off_t local_telldir(FsContext *ctx, V9fsFidOpenState *fs)
 {
 }
 
 static off_t local_telldir(FsContext *ctx, V9fsFidOpenState *fs)
 {

-    return telldir(fs->dir);
+    return telldir(fs->dir.stream);

 }
 
 }
 

-static int local_readdir_r(FsContext *ctx, V9fsFidOpenState *fs,
-                           struct dirent *entry,
-                           struct dirent **result)
+static bool local_is_mapped_file_metadata(FsContext *fs_ctx, const char *name)

 {
 {

-    int ret;
+    return !strcmp(name, VIRTFS_META_DIR);
+}
+
+static struct dirent *local_readdir(FsContext *ctx, V9fsFidOpenState *fs)
+{
+    struct dirent *entry;

 
 again:
 
 again:

-    ret = readdir_r(fs->dir, entry, result);
+    entry = readdir(fs->dir.stream);
+    if (!entry) {
+        return NULL;
+    }
+

     if (ctx->export_flags & V9FS_SM_MAPPED) {
         entry->d_type = DT_UNKNOWN;
     } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
     if (ctx->export_flags & V9FS_SM_MAPPED) {
         entry->d_type = DT_UNKNOWN;
     } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {

-        if (!ret && *result != NULL &&
-            !strcmp(entry->d_name, VIRTFS_META_DIR)) {
-            /* skp the meta data directory */
+        if (local_is_mapped_file_metadata(ctx, entry->d_name)) {
+            /* skip the meta data directory */

             goto again;
         }
         entry->d_type = DT_UNKNOWN;
     }
             goto again;
         }
         entry->d_type = DT_UNKNOWN;
     }

-    return ret;
+
+    return entry;

 }
 
 static void local_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
 {
 }
 
 static void local_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
 {

-    seekdir(fs->dir, off);
+    seekdir(fs->dir.stream, off);

 }
 
 static ssize_t local_preadv(FsContext *ctx, V9fsFidOpenState *fs,
 }
 
 static ssize_t local_preadv(FsContext *ctx, V9fsFidOpenState *fs,


@@ -431,8 +505,7 @@ static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
                              const struct iovec *iov,
                              int iovcnt, off_t offset)
 {
                              const struct iovec *iov,
                              int iovcnt, off_t offset)
 {

-    ssize_t ret
-;
+    ssize_t ret;

 #ifdef CONFIG_PREADV
     ret = pwritev(fs->fd, iov, iovcnt, offset);
 #else
 #ifdef CONFIG_PREADV
     ret = pwritev(fs->fd, iov, iovcnt, offset);
 #else


@@ -459,145 +532,134 @@ static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
 
 static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 {
 
 static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 {

-    char *buffer;
+    char *dirpath = g_path_get_dirname(fs_path->data);
+    char *name = g_path_get_basename(fs_path->data);

     int ret = -1;
     int ret = -1;

-    char *path = fs_path->data;
+    int dirfd;
+
+    dirfd = local_opendir_nofollow(fs_ctx, dirpath);
+    if (dirfd == -1) {
+        goto out;
+    }

 
     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 
     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {

-        buffer = rpath(fs_ctx, path);
-        ret = local_set_xattr(buffer, credp);
-        g_free(buffer);
+        ret = local_set_xattrat(dirfd, name, credp);

     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
     } 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)) {
-        buffer = rpath(fs_ctx, path);
-        ret = chmod(buffer, credp->fc_mode);
-        g_free(buffer);
+        ret = local_set_mapped_file_attrat(dirfd, name, credp);
+    } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
+               fs_ctx->export_flags & V9FS_SM_NONE) {
+        ret = fchmodat_nofollow(dirfd, name, credp->fc_mode);

     }
     }

+    close_preserve_errno(dirfd);
+
+out:
+    g_free(dirpath);
+    g_free(name);

     return ret;
 }
 
 static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
                        const char *name, FsCred *credp)
 {
     return ret;
 }
 
 static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
                        const char *name, FsCred *credp)
 {

-    char *path;

     int err = -1;
     int err = -1;

-    int serrno = 0;
-    V9fsString fullname;
-    char *buffer = NULL;
+    int dirfd;

 
 

-    v9fs_string_init(&fullname);
-    v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
-    path = fullname.data;
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+        local_is_mapped_file_metadata(fs_ctx, name)) {
+        errno = EINVAL;
+        return -1;
+    }

 
 

-    /* Determine the security model */
-    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
-        buffer = rpath(fs_ctx, path);
-        err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0);
+    dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
+    if (dirfd == -1) {
+        return -1;
+    }
+
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
+        fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        err = mknodat(dirfd, name, SM_LOCAL_MODE_BITS | S_IFREG, 0);

         if (err == -1) {
             goto out;
         }
         if (err == -1) {
             goto out;
         }

-        err = local_set_xattr(buffer, credp);
-        if (err == -1) {
-            serrno = errno;
-            goto err_end;
-        }
-    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {

 
 

-        buffer = rpath(fs_ctx, path);
-        err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0);
-        if (err == -1) {
-            goto out;
+        if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
+            err = local_set_xattrat(dirfd, name, credp);
+        } else {
+            err = local_set_mapped_file_attrat(dirfd, name, credp);

         }
         }

-        err = local_set_mapped_file_attr(fs_ctx, path, credp);

         if (err == -1) {
         if (err == -1) {

-            serrno = errno;

             goto err_end;
         }
             goto err_end;
         }

-    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
-               (fs_ctx->export_flags & V9FS_SM_NONE)) {
-        buffer = rpath(fs_ctx, path);
-        err = mknod(buffer, credp->fc_mode, credp->fc_rdev);
+    } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
+               fs_ctx->export_flags & V9FS_SM_NONE) {
+        err = mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev);

         if (err == -1) {
             goto out;
         }
         if (err == -1) {
             goto out;
         }

-        err = local_post_create_passthrough(fs_ctx, path, credp);
+        err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp);

         if (err == -1) {
         if (err == -1) {

-            serrno = errno;

             goto err_end;
         }
     }
     goto out;
 
 err_end:
             goto err_end;
         }
     }
     goto out;
 
 err_end:

-    remove(buffer);
-    errno = serrno;
+    unlinkat_preserve_errno(dirfd, name, 0);

 out:
 out:

-    g_free(buffer);
-    v9fs_string_free(&fullname);
+    close_preserve_errno(dirfd);

     return err;
 }
 
 static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
                        const char *name, FsCred *credp)
 {
     return err;
 }
 
 static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
                        const char *name, FsCred *credp)
 {

-    char *path;

     int err = -1;
     int err = -1;

-    int serrno = 0;
-    V9fsString fullname;
-    char *buffer = NULL;
+    int dirfd;

 
 

-    v9fs_string_init(&fullname);
-    v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
-    path = fullname.data;
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+        local_is_mapped_file_metadata(fs_ctx, name)) {
+        errno = EINVAL;
+        return -1;
+    }

 
 

-    /* Determine the security model */
-    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
-        buffer = rpath(fs_ctx, path);
-        err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
+    dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
+    if (dirfd == -1) {
+        return -1;
+    }
+
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
+        fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        err = mkdirat(dirfd, name, SM_LOCAL_DIR_MODE_BITS);

         if (err == -1) {
             goto out;
         }
         if (err == -1) {
             goto out;
         }

-        credp->fc_mode = credp->fc_mode|S_IFDIR;
-        err = local_set_xattr(buffer, credp);
-        if (err == -1) {
-            serrno = errno;
-            goto err_end;
-        }
-    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
-        buffer = rpath(fs_ctx, path);
-        err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
-        if (err == -1) {
-            goto out;
+        credp->fc_mode = credp->fc_mode | S_IFDIR;
+
+        if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
+            err = local_set_xattrat(dirfd, name, credp);
+        } else {
+            err = local_set_mapped_file_attrat(dirfd, name, credp);

         }
         }

-        credp->fc_mode = credp->fc_mode|S_IFDIR;
-        err = local_set_mapped_file_attr(fs_ctx, path, credp);

         if (err == -1) {
         if (err == -1) {

-            serrno = errno;

             goto err_end;
         }
             goto err_end;
         }

-    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
-               (fs_ctx->export_flags & V9FS_SM_NONE)) {
-        buffer = rpath(fs_ctx, path);
-        err = mkdir(buffer, credp->fc_mode);
+    } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
+               fs_ctx->export_flags & V9FS_SM_NONE) {
+        err = mkdirat(dirfd, name, credp->fc_mode);

         if (err == -1) {
             goto out;
         }
         if (err == -1) {
             goto out;
         }

-        err = local_post_create_passthrough(fs_ctx, path, credp);
+        err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp);

         if (err == -1) {
         if (err == -1) {

-            serrno = errno;

             goto err_end;
         }
     }
     goto out;
 
 err_end:
             goto err_end;
         }
     }
     goto out;
 
 err_end:

-    remove(buffer);
-    errno = serrno;
+    unlinkat_preserve_errno(dirfd, name, AT_REMOVEDIR);

 out:
 out:

-    g_free(buffer);
-    v9fs_string_free(&fullname);
+    close_preserve_errno(dirfd);

     return err;
 }
 
     return err;
 }
 


@@ -607,7 +669,7 @@ static int local_fstat(FsContext *fs_ctx, int fid_type,
     int err, fd;
 
     if (fid_type == P9_FID_DIR) {
     int err, fd;
 
     if (fid_type == P9_FID_DIR) {

-        fd = dirfd(fs->dir);
+        fd = dirfd(fs->dir.stream);

     } else {
         fd = fs->fd;
     }
     } else {
         fd = fs->fd;
     }


@@ -645,62 +707,51 @@ static int local_fstat(FsContext *fs_ctx, int fid_type,
 static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
                        int flags, FsCred *credp, V9fsFidOpenState *fs)
 {
 static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
                        int flags, FsCred *credp, V9fsFidOpenState *fs)
 {

-    char *path;

     int fd = -1;
     int err = -1;
     int fd = -1;
     int err = -1;

-    int serrno = 0;
-    V9fsString fullname;
-    char *buffer = NULL;
+    int dirfd;
+
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+        local_is_mapped_file_metadata(fs_ctx, name)) {
+        errno = EINVAL;
+        return -1;
+    }

 
     /*
      * Mark all the open to not follow symlinks
      */
     flags |= O_NOFOLLOW;
 
 
     /*
      * Mark all the open to not follow symlinks
      */
     flags |= O_NOFOLLOW;
 

-    v9fs_string_init(&fullname);
-    v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
-    path = fullname.data;
+    dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
+    if (dirfd == -1) {
+        return -1;
+    }

 
     /* Determine the security model */
 
     /* Determine the security model */

-    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
-        buffer = rpath(fs_ctx, path);
-        fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
+        fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        fd = openat_file(dirfd, name, flags, SM_LOCAL_MODE_BITS);

         if (fd == -1) {
         if (fd == -1) {

-            err = fd;

             goto out;
         }
         credp->fc_mode = credp->fc_mode|S_IFREG;
             goto out;
         }
         credp->fc_mode = credp->fc_mode|S_IFREG;

-        /* Set cleint credentials in xattr */
-        err = local_set_xattr(buffer, credp);
-        if (err == -1) {
-            serrno = errno;
-            goto err_end;
+        if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
+            /* Set cleint credentials in xattr */
+            err = local_set_xattrat(dirfd, name, credp);
+        } else {
+            err = local_set_mapped_file_attrat(dirfd, name, credp);

         }
         }

-    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
-        buffer = rpath(fs_ctx, path);
-        fd = open(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) {
         if (err == -1) {

-            serrno = errno;

             goto err_end;
         }
     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {
             goto err_end;
         }
     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {

-        buffer = rpath(fs_ctx, path);
-        fd = open(buffer, flags, credp->fc_mode);
+        fd = openat_file(dirfd, name, flags, credp->fc_mode);

         if (fd == -1) {
         if (fd == -1) {

-            err = fd;

             goto out;
         }
             goto out;
         }

-        err = local_post_create_passthrough(fs_ctx, path, credp);
+        err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp);

         if (err == -1) {
         if (err == -1) {

-            serrno = errno;

             goto err_end;
         }
     }
             goto err_end;
         }
     }


@@ -709,12 +760,11 @@ static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
     goto out;
 
 err_end:
     goto out;
 
 err_end:

-    close(fd);
-    remove(buffer);
-    errno = serrno;
+    unlinkat_preserve_errno(dirfd, name,
+                            flags & O_DIRECTORY ? AT_REMOVEDIR : 0);
+    close_preserve_errno(fd);

 out:
 out:

-    g_free(buffer);
-    v9fs_string_free(&fullname);
+    close_preserve_errno(dirfd);

     return err;
 }
 
     return err;
 }
 


@@ -723,23 +773,28 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
                          V9fsPath *dir_path, const char *name, FsCred *credp)
 {
     int err = -1;
                          V9fsPath *dir_path, const char *name, FsCred *credp)
 {
     int err = -1;

-    int serrno = 0;
-    char *newpath;
-    V9fsString fullname;
-    char *buffer = NULL;
+    int dirfd;

 
 

-    v9fs_string_init(&fullname);
-    v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
-    newpath = fullname.data;
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+        local_is_mapped_file_metadata(fs_ctx, name)) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
+    if (dirfd == -1) {
+        return -1;
+    }

 
     /* Determine the security model */
 
     /* Determine the security model */

-    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;
         ssize_t oldpath_size, write_size;
         int fd;
         ssize_t oldpath_size, write_size;

-        buffer = rpath(fs_ctx, newpath);
-        fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
+
+        fd = openat_file(dirfd, name, O_CREAT | O_EXCL | O_RDWR,
+                         SM_LOCAL_MODE_BITS);

         if (fd == -1) {
         if (fd == -1) {

-            err = fd;

             goto out;
         }
         /* Write the oldpath (target) to the file. */
             goto out;
         }
         /* Write the oldpath (target) to the file. */


@@ -747,218 +802,210 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
         do {
             write_size = write(fd, (void *)oldpath, oldpath_size);
         } while (write_size == -1 && errno == EINTR);
         do {
             write_size = write(fd, (void *)oldpath, oldpath_size);
         } while (write_size == -1 && errno == EINTR);

+        close_preserve_errno(fd);

 
         if (write_size != oldpath_size) {
 
         if (write_size != oldpath_size) {

-            serrno = errno;
-            close(fd);
-            err = -1;

             goto err_end;
         }
             goto err_end;
         }

-        close(fd);

         /* Set cleint credentials in symlink's xattr */
         /* Set cleint credentials in symlink's xattr */

-        credp->fc_mode = credp->fc_mode|S_IFLNK;
-        err = local_set_xattr(buffer, credp);
-        if (err == -1) {
-            serrno = errno;
-            goto err_end;
-        }
-    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
-        int fd;
-        ssize_t oldpath_size, write_size;
-        buffer = rpath(fs_ctx, newpath);
-        fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, 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);
+        credp->fc_mode = credp->fc_mode | S_IFLNK;

 
 

-        if (write_size != oldpath_size) {
-            serrno = errno;
-            close(fd);
-            err = -1;
-            goto err_end;
+        if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
+            err = local_set_xattrat(dirfd, name, credp);
+        } else {
+            err = local_set_mapped_file_attrat(dirfd, name, credp);

         }
         }

-        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) {
         if (err == -1) {

-            serrno = errno;

             goto err_end;
         }
             goto err_end;
         }

-    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
-               (fs_ctx->export_flags & V9FS_SM_NONE)) {
-        buffer = rpath(fs_ctx, newpath);
-        err = symlink(oldpath, buffer);
+    } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
+               fs_ctx->export_flags & V9FS_SM_NONE) {
+        err = symlinkat(oldpath, dirfd, name);

         if (err) {
             goto out;
         }
         if (err) {
             goto out;
         }

-        err = lchown(buffer, credp->fc_uid, credp->fc_gid);
+        err = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,
+                       AT_SYMLINK_NOFOLLOW);

         if (err == -1) {
             /*
              * If we fail to change ownership and if we are
              * using security model none. Ignore the error
              */
             if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
         if (err == -1) {
             /*
              * If we fail to change ownership and if we are
              * using security model none. Ignore the error
              */
             if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {

-                serrno = errno;

                 goto err_end;
                 goto err_end;

-            } else
+            } else {

                 err = 0;
                 err = 0;

+            }

         }
     }
     goto out;
 
 err_end:
         }
     }
     goto out;
 
 err_end:

-    remove(buffer);
-    errno = serrno;
+    unlinkat_preserve_errno(dirfd, name, 0);

 out:
 out:

-    g_free(buffer);
-    v9fs_string_free(&fullname);
+    close_preserve_errno(dirfd);

     return err;
 }
 
 static int local_link(FsContext *ctx, V9fsPath *oldpath,
                       V9fsPath *dirpath, const char *name)
 {
     return err;
 }
 
 static int local_link(FsContext *ctx, V9fsPath *oldpath,
                       V9fsPath *dirpath, const char *name)
 {

-    int ret;
-    V9fsString newpath;
-    char *buffer, *buffer1;
+    char *odirpath = g_path_get_dirname(oldpath->data);
+    char *oname = g_path_get_basename(oldpath->data);
+    int ret = -1;
+    int odirfd, ndirfd;
+
+    if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+        local_is_mapped_file_metadata(ctx, name)) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    odirfd = local_opendir_nofollow(ctx, odirpath);
+    if (odirfd == -1) {
+        goto out;
+    }

 
 

-    v9fs_string_init(&newpath);
-    v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
+    ndirfd = local_opendir_nofollow(ctx, dirpath->data);
+    if (ndirfd == -1) {
+        close_preserve_errno(odirfd);
+        goto out;
+    }

 
 

-    buffer = rpath(ctx, oldpath->data);
-    buffer1 = rpath(ctx, newpath.data);
-    ret = link(buffer, buffer1);
-    g_free(buffer);
-    g_free(buffer1);
+    ret = linkat(odirfd, oname, ndirfd, name, 0);
+    if (ret < 0) {
+        goto out_close;
+    }

 
     /* now link the virtfs_metadata files */
 
     /* 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;
+    if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        int omap_dirfd, nmap_dirfd;
+
+        ret = mkdirat(ndirfd, VIRTFS_META_DIR, 0700);
+        if (ret < 0 && errno != EEXIST) {
+            goto err_undo_link;

         }
         }

-        buffer = local_mapped_attr_path(ctx, oldpath->data);
-        buffer1 = local_mapped_attr_path(ctx, newpath.data);
-        ret = link(buffer, buffer1);
-        g_free(buffer);
-        g_free(buffer1);
+
+        omap_dirfd = openat_dir(odirfd, VIRTFS_META_DIR);
+        if (omap_dirfd == -1) {
+            goto err;
+        }
+
+        nmap_dirfd = openat_dir(ndirfd, VIRTFS_META_DIR);
+        if (nmap_dirfd == -1) {
+            close_preserve_errno(omap_dirfd);
+            goto err;
+        }
+
+        ret = linkat(omap_dirfd, oname, nmap_dirfd, name, 0);
+        close_preserve_errno(nmap_dirfd);
+        close_preserve_errno(omap_dirfd);

         if (ret < 0 && errno != ENOENT) {
         if (ret < 0 && errno != ENOENT) {

-            goto err_out;
+            goto err_undo_link;

         }
         }

-    }
-err_out:
-    v9fs_string_free(&newpath);
-    return ret;
-}

 
 

-static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
-{
-    char *buffer;
-    int ret;
-    char *path = fs_path->data;
+        ret = 0;
+    }
+    goto out_close;

 
 

-    buffer = rpath(ctx, path);
-    ret = truncate(buffer, size);
-    g_free(buffer);
+err:
+    ret = -1;
+err_undo_link:
+    unlinkat_preserve_errno(ndirfd, name, 0);
+out_close:
+    close_preserve_errno(ndirfd);
+    close_preserve_errno(odirfd);
+out:
+    g_free(oname);
+    g_free(odirpath);

     return ret;
 }
 
     return ret;
 }
 

-static int local_rename(FsContext *ctx, const char *oldpath,
-                        const char *newpath)
+static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)

 {
 {

-    int err;
-    char *buffer, *buffer1;
+    int fd, ret;

 
 

-    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 */
-        buffer = local_mapped_attr_path(ctx, oldpath);
-        buffer1 = local_mapped_attr_path(ctx, newpath);
-        err = rename(buffer, buffer1);
-        g_free(buffer);
-        g_free(buffer1);
-        if (err < 0 && errno != ENOENT) {
-            return err;
-        }
+    fd = local_open_nofollow(ctx, fs_path->data, O_WRONLY, 0);
+    if (fd == -1) {
+        return -1;

     }
     }

-
-    buffer = rpath(ctx, oldpath);
-    buffer1 = rpath(ctx, newpath);
-    err = rename(buffer, buffer1);
-    g_free(buffer);
-    g_free(buffer1);
-    return err;
+    ret = ftruncate(fd, size);
+    close_preserve_errno(fd);
+    return ret;

 }
 
 static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 {
 }
 
 static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 {

-    char *buffer;
+    char *dirpath = g_path_get_dirname(fs_path->data);
+    char *name = g_path_get_basename(fs_path->data);

     int ret = -1;
     int ret = -1;

-    char *path = fs_path->data;
+    int dirfd;
+
+    dirfd = local_opendir_nofollow(fs_ctx, dirpath);
+    if (dirfd == -1) {
+        goto out;
+    }

 
     if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
         (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
         (fs_ctx->export_flags & V9FS_SM_NONE)) {
 
     if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
         (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
         (fs_ctx->export_flags & V9FS_SM_NONE)) {

-        buffer = rpath(fs_ctx, path);
-        ret = lchown(buffer, credp->fc_uid, credp->fc_gid);
-        g_free(buffer);
+        ret = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,
+                       AT_SYMLINK_NOFOLLOW);

     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {

-        buffer = rpath(fs_ctx, path);
-        ret = local_set_xattr(buffer, credp);
-        g_free(buffer);
+        ret = local_set_xattrat(dirfd, name, credp);

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

-        return local_set_mapped_file_attr(fs_ctx, path, credp);
+        ret = local_set_mapped_file_attrat(dirfd, name, credp);

     }
     }

+
+    close_preserve_errno(dirfd);
+out:
+    g_free(name);
+    g_free(dirpath);

     return ret;
 }
 
 static int local_utimensat(FsContext *s, V9fsPath *fs_path,
                            const struct timespec *buf)
 {
     return ret;
 }
 
 static int local_utimensat(FsContext *s, V9fsPath *fs_path,
                            const struct timespec *buf)
 {

-    char *buffer;
-    int ret;
-    char *path = fs_path->data;
+    char *dirpath = g_path_get_dirname(fs_path->data);
+    char *name = g_path_get_basename(fs_path->data);
+    int dirfd, ret = -1;
+
+    dirfd = local_opendir_nofollow(s, dirpath);
+    if (dirfd == -1) {
+        goto out;
+    }

 
 

-    buffer = rpath(s, path);
-    ret = qemu_utimens(buffer, buf);
-    g_free(buffer);
+    ret = utimensat(dirfd, name, buf, AT_SYMLINK_NOFOLLOW);
+    close_preserve_errno(dirfd);
+out:
+    g_free(dirpath);
+    g_free(name);

     return ret;
 }
 
     return ret;
 }
 

-static int local_remove(FsContext *ctx, const char *path)
+static int local_unlinkat_common(FsContext *ctx, int dirfd, const char *name,
+                                 int flags)

 {
 {

-    int err;
-    struct stat stbuf;
-    char *buffer;
+    int ret = -1;

 
     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 
     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {

-        buffer = rpath(ctx, path);
-        err =  lstat(buffer, &stbuf);
-        g_free(buffer);
-        if (err) {
-            goto err_out;
-        }
-        /*
-         * If directory remove .virtfs_metadata contained in the
-         * directory
-         */
-        if (S_ISDIR(stbuf.st_mode)) {
-            buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root,
-                                     path, VIRTFS_META_DIR);
-            err = remove(buffer);
-            g_free(buffer);
-            if (err < 0 && errno != ENOENT) {
+        int map_dirfd;
+
+        if (flags == AT_REMOVEDIR) {
+            int fd;
+
+            fd = openat_dir(dirfd, name);
+            if (fd == -1) {
+                goto err_out;
+            }
+            /*
+             * If directory remove .virtfs_metadata contained in the
+             * directory
+             */
+            ret = unlinkat(fd, VIRTFS_META_DIR, AT_REMOVEDIR);
+            close_preserve_errno(fd);
+            if (ret < 0 && errno != ENOENT) {

                 /*
                  * We didn't had the .virtfs_metadata file. May be file created
                  * in non-mapped mode ?. Ignore ENOENT.
                 /*
                  * We didn't had the .virtfs_metadata file. May be file created
                  * in non-mapped mode ?. Ignore ENOENT.


@@ -968,12 +1015,12 @@ static int local_remove(FsContext *ctx, const char *path)
         }
         /*
          * Now remove the name from parent directory
         }
         /*
          * Now remove the name from parent directory

-         * .virtfs_metadata directory
+         * .virtfs_metadata directory.

          */
          */

-        buffer = local_mapped_attr_path(ctx, path);
-        err = remove(buffer);
-        g_free(buffer);
-        if (err < 0 && errno != ENOENT) {
+        map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR);
+        ret = unlinkat(map_dirfd, name, 0);
+        close_preserve_errno(map_dirfd);
+        if (ret < 0 && errno != ENOENT) {

             /*
              * We didn't had the .virtfs_metadata file. May be file created
              * in non-mapped mode ?. Ignore ENOENT.
             /*
              * We didn't had the .virtfs_metadata file. May be file created
              * in non-mapped mode ?. Ignore ENOENT.


@@ -982,10 +1029,39 @@ static int local_remove(FsContext *ctx, const char *path)
         }
     }
 
         }
     }
 

-    buffer = rpath(ctx, path);
-    err = remove(buffer);
-    g_free(buffer);
+    ret = unlinkat(dirfd, name, flags);

 err_out:
 err_out:

+    return ret;
+}
+
+static int local_remove(FsContext *ctx, const char *path)
+{
+    struct stat stbuf;
+    char *dirpath = g_path_get_dirname(path);
+    char *name = g_path_get_basename(path);
+    int flags = 0;
+    int dirfd;
+    int err = -1;
+
+    dirfd = local_opendir_nofollow(ctx, dirpath);
+    if (dirfd == -1) {
+        goto out;
+    }
+
+    if (fstatat(dirfd, path, &stbuf, AT_SYMLINK_NOFOLLOW) < 0) {
+        goto err_out;
+    }
+
+    if (S_ISDIR(stbuf.st_mode)) {
+        flags |= AT_REMOVEDIR;
+    }
+
+    err = local_unlinkat_common(ctx, dirfd, name, flags);
+err_out:
+    close_preserve_errno(dirfd);
+out:
+    g_free(name);
+    g_free(dirpath);

     return err;
 }
 
     return err;
 }
 


@@ -995,7 +1071,7 @@ static int local_fsync(FsContext *ctx, int fid_type,
     int fd;
 
     if (fid_type == P9_FID_DIR) {
     int fd;
 
     if (fid_type == P9_FID_DIR) {

-        fd = dirfd(fs->dir);
+        fd = dirfd(fs->dir.stream);

     } else {
         fd = fs->fd;
     }
     } else {
         fd = fs->fd;
     }


@@ -1009,13 +1085,14 @@ static int local_fsync(FsContext *ctx, int fid_type,
 
 static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
 {
 
 static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
 {

-    char *buffer;
-    int ret;
-    char *path = fs_path->data;
+    int fd, ret;

 
 

-    buffer = rpath(s, path);
-    ret = statfs(buffer, stbuf);
-    g_free(buffer);
+    fd = local_open_nofollow(s, fs_path->data, O_RDONLY, 0);
+    if (fd == -1) {
+        return -1;
+    }
+    ret = fstatfs(fd, stbuf);
+    close_preserve_errno(fd);

     return ret;
 }
 
     return ret;
 }
 


@@ -1054,14 +1131,22 @@ static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
 static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
                               const char *name, V9fsPath *target)
 {
 static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
                               const char *name, V9fsPath *target)
 {

+    if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+        local_is_mapped_file_metadata(ctx, name)) {
+        errno = EINVAL;
+        return -1;
+    }
+

     if (dir_path) {
     if (dir_path) {

-        v9fs_string_sprintf((V9fsString *)target, "%s/%s",
-                            dir_path->data, name);
+        v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
+    } else if (strcmp(name, "/")) {
+        v9fs_path_sprintf(target, "%s", name);

     } else {
     } else {

-        v9fs_string_sprintf((V9fsString *)target, "%s", name);
+        /* We want the path of the export root to be relative, otherwise
+         * "*at()" syscalls would treat it as "/" in the host.
+         */
+        v9fs_path_sprintf(target, "%s", ".");

     }
     }

-    /* Bump the size for including terminating NULL */
-    target->size++;

     return 0;
 }
 
     return 0;
 }
 


@@ -1070,70 +1155,118 @@ static int local_renameat(FsContext *ctx, V9fsPath *olddir,
                           const char *new_name)
 {
     int ret;
                           const char *new_name)
 {
     int ret;

-    V9fsString old_full_name, new_full_name;
+    int odirfd, ndirfd;
+
+    if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+        (local_is_mapped_file_metadata(ctx, old_name) ||
+         local_is_mapped_file_metadata(ctx, new_name))) {
+        errno = EINVAL;
+        return -1;
+    }

 
 

-    v9fs_string_init(&old_full_name);
-    v9fs_string_init(&new_full_name);
+    odirfd = local_opendir_nofollow(ctx, olddir->data);
+    if (odirfd == -1) {
+        return -1;
+    }

 
 

-    v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name);
-    v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name);
+    ndirfd = local_opendir_nofollow(ctx, newdir->data);
+    if (ndirfd == -1) {
+        close_preserve_errno(odirfd);
+        return -1;
+    }

 
 

-    ret = local_rename(ctx, old_full_name.data, new_full_name.data);
-    v9fs_string_free(&old_full_name);
-    v9fs_string_free(&new_full_name);
+    ret = renameat(odirfd, old_name, ndirfd, new_name);
+    if (ret < 0) {
+        goto out;
+    }
+
+    if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+        int omap_dirfd, nmap_dirfd;
+
+        ret = mkdirat(ndirfd, VIRTFS_META_DIR, 0700);
+        if (ret < 0 && errno != EEXIST) {
+            goto err_undo_rename;
+        }
+
+        omap_dirfd = openat_dir(odirfd, VIRTFS_META_DIR);
+        if (omap_dirfd == -1) {
+            goto err;
+        }
+
+        nmap_dirfd = openat_dir(ndirfd, VIRTFS_META_DIR);
+        if (nmap_dirfd == -1) {
+            close_preserve_errno(omap_dirfd);
+            goto err;
+        }
+
+        /* rename the .virtfs_metadata files */
+        ret = renameat(omap_dirfd, old_name, nmap_dirfd, new_name);
+        close_preserve_errno(nmap_dirfd);
+        close_preserve_errno(omap_dirfd);
+        if (ret < 0 && errno != ENOENT) {
+            goto err_undo_rename;
+        }
+
+        ret = 0;
+    }
+    goto out;
+
+err:
+    ret = -1;
+err_undo_rename:
+    renameat_preserve_errno(ndirfd, new_name, odirfd, old_name);
+out:
+    close_preserve_errno(ndirfd);
+    close_preserve_errno(odirfd);

     return ret;
 }
 
     return ret;
 }
 

+static void v9fs_path_init_dirname(V9fsPath *path, const char *str)
+{
+    path->data = g_path_get_dirname(str);
+    path->size = strlen(path->data) + 1;
+}
+
+static int local_rename(FsContext *ctx, const char *oldpath,
+                        const char *newpath)
+{
+    int err;
+    char *oname = g_path_get_basename(oldpath);
+    char *nname = g_path_get_basename(newpath);
+    V9fsPath olddir, newdir;
+
+    v9fs_path_init_dirname(&olddir, oldpath);
+    v9fs_path_init_dirname(&newdir, newpath);
+
+    err = local_renameat(ctx, &olddir, oname, &newdir, nname);
+
+    v9fs_path_free(&newdir);
+    v9fs_path_free(&olddir);
+    g_free(nname);
+    g_free(oname);
+
+    return err;
+}
+

 static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
                           const char *name, int flags)
 {
     int ret;
 static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
                           const char *name, int flags)
 {
     int ret;

-    V9fsString fullname;
-    char *buffer;
+    int dirfd;

 
 

-    v9fs_string_init(&fullname);
+    if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+        local_is_mapped_file_metadata(ctx, name)) {
+        errno = EINVAL;
+        return -1;
+    }

 
 

-    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
-             */
-            buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root,
-                                     fullname.data, VIRTFS_META_DIR);
-            ret = remove(buffer);
-            g_free(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.
-         */
-        buffer = local_mapped_attr_path(ctx, fullname.data);
-        ret = remove(buffer);
-        g_free(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;
-        }
+    dirfd = local_opendir_nofollow(ctx, dir->data);
+    if (dirfd == -1) {
+        return -1;

     }
     }

-    /* Remove the name finally */
-    buffer = rpath(ctx, fullname.data);
-    ret = remove(buffer);
-    g_free(buffer);

 
 

-err_out:
-    v9fs_string_free(&fullname);
+    ret = local_unlinkat_common(ctx, dirfd, name, flags);
+    close_preserve_errno(dirfd);

     return ret;
 }
 
     return ret;
 }
 


@@ -1167,8 +1300,31 @@ static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
 
 static int local_init(FsContext *ctx)
 {
 
 static int local_init(FsContext *ctx)
 {

-    int err = 0;

     struct statfs stbuf;
     struct statfs stbuf;

+    LocalData *data = g_malloc(sizeof(*data));
+
+    data->mountfd = open(ctx->fs_root, O_DIRECTORY | O_RDONLY);
+    if (data->mountfd == -1) {
+        goto err;
+    }
+
+#ifdef FS_IOC_GETVERSION
+    /*
+     * use ioc_getversion only if the ioctl is definied
+     */
+    if (fstatfs(data->mountfd, &stbuf) < 0) {
+        close_preserve_errno(data->mountfd);
+        goto err;
+    }
+    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 = local_ioc_getversion;
+        break;
+    }
+#endif

 
     if (ctx->export_flags & V9FS_SM_PASSTHROUGH) {
         ctx->xops = passthrough_xattr_ops;
 
     if (ctx->export_flags & V9FS_SM_PASSTHROUGH) {
         ctx->xops = passthrough_xattr_ops;


@@ -1184,34 +1340,33 @@ static int local_init(FsContext *ctx)
         ctx->xops = passthrough_xattr_ops;
     }
     ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
         ctx->xops = passthrough_xattr_ops;
     }
     ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;

-#ifdef FS_IOC_GETVERSION
-    /*
-     * use ioc_getversion only if the iocl is definied
-     */
-    err = statfs(ctx->fs_root, &stbuf);
-    if (!err) {
-        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 = local_ioc_getversion;
-            break;
-        }
-    }
-#endif
-    return err;
+
+    ctx->private = data;
+    return 0;
+
+err:
+    g_free(data);
+    return -1;
+}
+
+static void local_cleanup(FsContext *ctx)
+{
+    LocalData *data = ctx->private;
+
+    close(data->mountfd);
+    g_free(data);

 }
 
 static int local_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");
 }
 
 static int local_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");

+    Error *err = NULL;

 
     if (!sec_model) {
 
     if (!sec_model) {

-        fprintf(stderr, "security model not specified, "
-                "local fs needs security model\nvalid options are:"
-                "\tsecurity_model=[passthrough|mapped|none]\n");
+        error_report("Security model not specified, local fs needs security model");
+        error_printf("valid options are:"
+                     "\tsecurity_model=[passthrough|mapped-xattr|mapped-file|none]\n");

         return -1;
     }
 
         return -1;
     }
 


@@ -1225,16 +1380,23 @@ static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
     } else if (!strcmp(sec_model, "mapped-file")) {
         fse->export_flags |= V9FS_SM_MAPPED_FILE;
     } else {
     } 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-xattr|mapped-file|none]\n",
-                sec_model);
+        error_report("Invalid security model %s specified", sec_model);
+        error_printf("valid options are:"
+                     "\t[passthrough|mapped-xattr|mapped-file|none]\n");

         return -1;
     }
 
     if (!path) {
         return -1;
     }
 
     if (!path) {

-        fprintf(stderr, "fsdev: No path specified.\n");
+        error_report("fsdev: No path specified");
+        return -1;
+    }
+
+    fsdev_throttle_parse_opts(opts, &fse->fst, &err);
+    if (err) {
+        error_reportf_err(err, "Throttle configuration is not valid: ");

         return -1;
     }
         return -1;
     }

+

     fse->path = g_strdup(path);
 
     return 0;
     fse->path = g_strdup(path);
 
     return 0;


@@ -1243,6 +1405,7 @@ static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
 FileOperations local_ops = {
     .parse_opts = local_parse_opts,
     .init  = local_init,
 FileOperations local_ops = {
     .parse_opts = local_parse_opts,
     .init  = local_init,

+    .cleanup = local_cleanup,

     .lstat = local_lstat,
     .readlink = local_readlink,
     .close = local_close,
     .lstat = local_lstat,
     .readlink = local_readlink,
     .close = local_close,


@@ -1251,7 +1414,7 @@ FileOperations local_ops = {
     .opendir = local_opendir,
     .rewinddir = local_rewinddir,
     .telldir = local_telldir,
     .opendir = local_opendir,
     .rewinddir = local_rewinddir,
     .telldir = local_telldir,

-    .readdir_r = local_readdir_r,
+    .readdir = local_readdir,

     .seekdir = local_seekdir,
     .preadv = local_preadv,
     .pwritev = local_pwritev,
     .seekdir = local_seekdir,
     .preadv = local_preadv,
     .pwritev = local_pwritev,