add System Compression support
[wimlib] / src / unix_capture.c
index dd79b65..2843c36 100644 (file)
@@ -3,22 +3,20 @@
  */
 
 /*
- * Copyright (C) 2012, 2013 Eric Biggers
+ * Copyright (C) 2012, 2013, 2014 Eric Biggers
  *
- * This file is part of wimlib, a library for working with WIM files.
+ * This file is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your option) any
+ * later version.
  *
- * wimlib is free software; you can redistribute it and/or modify it under the
- * terms of the GNU General Public License as published by the Free
- * Software Foundation; either version 3 of the License, or (at your option)
- * any later version.
- *
- * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
- * A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * This file is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
  * details.
  *
- * You should have received a copy of the GNU General Public License
- * along with wimlib; if not, see http://www.gnu.org/licenses/.
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this file; if not, see http://www.gnu.org/licenses/.
  */
 
 #ifndef __WIN32__
 
 #include <dirent.h>
 #include <errno.h>
-#include <limits.h>
+#include <fcntl.h>
+#include <limits.h> /* for PATH_MAX */
 #include <sys/stat.h>
 #include <unistd.h>
 
+#include "wimlib/blob_table.h"
 #include "wimlib/capture.h"
 #include "wimlib/dentry.h"
 #include "wimlib/error.h"
-#include "wimlib/lookup_table.h"
-#include "wimlib/paths.h"
 #include "wimlib/reparse.h"
 #include "wimlib/timestamp.h"
+#include "wimlib/unix_data.h"
+
+#ifdef HAVE_FDOPENDIR
+#  define my_fdopendir(dirfd_p) fdopendir(*(dirfd_p))
+#else
+static DIR *
+my_fdopendir(int *dirfd_p)
+{
+       DIR *dir = NULL;
+       int old_pwd;
+
+       old_pwd = open(".", O_RDONLY);
+       if (old_pwd >= 0) {
+               if (!fchdir(*dirfd_p)) {
+                       dir = opendir(".");
+                       if (dir) {
+                               close(*dirfd_p);
+                               *dirfd_p = dirfd(dir);
+                       }
+                       fchdir(old_pwd);
+               }
+               close(old_pwd);
+       }
+       return dir;
+}
+#endif
+
+#ifdef HAVE_OPENAT
+#  define my_openat(full_path, dirfd, relpath, flags) \
+               openat((dirfd), (relpath), (flags))
+#else
+#  define my_openat(full_path, dirfd, relpath, flags) \
+               open((full_path), (flags))
+#endif
+
+#ifdef HAVE_READLINKAT
+#  define my_readlinkat(full_path, dirfd, relpath, buf, bufsize) \
+               readlinkat((dirfd), (relpath), (buf), (bufsize))
+#else
+#  define my_readlinkat(full_path, dirfd, relpath, buf, bufsize) \
+               readlink((full_path), (buf), (bufsize))
+#endif
+
+#ifdef HAVE_FSTATAT
+#  define my_fstatat(full_path, dirfd, relpath, stbuf, flags)  \
+       fstatat((dirfd), (relpath), (stbuf), (flags))
+#else
+#  define my_fstatat(full_path, dirfd, relpath, stbuf, flags)  \
+       ((flags) & AT_SYMLINK_NOFOLLOW) ? \
+               lstat((full_path), (stbuf)) : \
+               stat((full_path), (stbuf))
+#endif
+
+#ifndef AT_FDCWD
+#  define AT_FDCWD     -100
+#endif
+
+#ifndef AT_SYMLINK_NOFOLLOW
+#  define AT_SYMLINK_NOFOLLOW  0x100
+#endif
 
 static int
-unix_capture_regular_file(const char *path,
-                         u64 size,
-                         struct wim_inode *inode,
-                         struct list_head *unhashed_streams)
+unix_scan_regular_file(const char *path, u64 size, struct wim_inode *inode,
+                      struct list_head *unhashed_blobs)
 {
+       struct blob_descriptor *blob = NULL;
+       struct wim_inode_stream *strm;
+
        inode->i_attributes = FILE_ATTRIBUTE_NORMAL;
 
-       /* Empty files do not have to have a lookup table entry. */
-       if (size != 0) {
-               struct wim_lookup_table_entry *lte;
-               char *file_on_disk;
-
-               file_on_disk = STRDUP(path);
-               if (!file_on_disk)
-                       return WIMLIB_ERR_NOMEM;
-               lte = new_lookup_table_entry();
-               if (!lte) {
-                       FREE(file_on_disk);
-                       return WIMLIB_ERR_NOMEM;
-               }
-               lte->file_on_disk = file_on_disk;
-               lte->resource_location = RESOURCE_IN_FILE_ON_DISK;
-               lte->size = size;
-               add_unhashed_stream(lte, inode, 0, unhashed_streams);
-               inode->i_lte = lte;
+       if (size) {
+               blob = new_blob_descriptor();
+               if (unlikely(!blob))
+                       goto err_nomem;
+               blob->file_on_disk = STRDUP(path);
+               if (unlikely(!blob->file_on_disk))
+                       goto err_nomem;
+               blob->blob_location = BLOB_IN_FILE_ON_DISK;
+               blob->size = size;
+               blob->file_inode = inode;
        }
+
+       strm = inode_add_stream(inode, STREAM_TYPE_DATA, NO_STREAM_NAME, blob);
+       if (unlikely(!strm))
+               goto err_nomem;
+
+       prepare_unhashed_blob(blob, inode, strm->stream_id, unhashed_blobs);
        return 0;
+
+err_nomem:
+       free_blob_descriptor(blob);
+       return WIMLIB_ERR_NOMEM;
 }
 
 static int
-unix_build_dentry_tree_recursive(struct wim_dentry **root_ret,
-                                char *path,
-                                size_t path_len,
-                                struct add_image_params *params);
+unix_build_dentry_tree_recursive(struct wim_dentry **tree_ret,
+                                char *path, size_t path_len,
+                                int dirfd, const char *relpath,
+                                struct capture_params *params);
 
 static int
-unix_capture_directory(struct wim_dentry *dir_dentry,
-                      char *path,
-                      size_t path_len,
-                      struct add_image_params *params)
+unix_scan_directory(struct wim_dentry *dir_dentry,
+                   char *full_path, size_t full_path_len,
+                   int parent_dirfd, const char *dir_relpath,
+                   struct capture_params *params)
 {
 
+       int dirfd;
        DIR *dir;
-       struct dirent *entry;
-       struct wim_dentry *child;
        int ret;
 
+       dirfd = my_openat(full_path, parent_dirfd, dir_relpath, O_RDONLY);
+       if (dirfd < 0) {
+               ERROR_WITH_ERRNO("\"%s\": Can't open directory", full_path);
+               return WIMLIB_ERR_OPENDIR;
+       }
+
        dir_dentry->d_inode->i_attributes = FILE_ATTRIBUTE_DIRECTORY;
-       dir = opendir(path);
+       dir = my_fdopendir(&dirfd);
        if (!dir) {
-               ERROR_WITH_ERRNO("Failed to open the directory `%s'",
-                                path);
+               ERROR_WITH_ERRNO("\"%s\": Can't open directory", full_path);
+               close(dirfd);
                return WIMLIB_ERR_OPENDIR;
        }
 
-       /* Recurse on directory contents */
        ret = 0;
        for (;;) {
+               struct dirent *entry;
+               struct wim_dentry *child;
+               size_t name_len;
+
                errno = 0;
                entry = readdir(dir);
                if (!entry) {
                        if (errno) {
                                ret = WIMLIB_ERR_READ;
-                               ERROR_WITH_ERRNO("Error reading the "
-                                                "directory `%s'", path);
+                               ERROR_WITH_ERRNO("\"%s\": Error reading directory",
+                                                full_path);
                        }
                        break;
                }
 
-               if (entry->d_name[0] == '.' && (entry->d_name[1] == '\0'
-                     || (entry->d_name[1] == '.' && entry->d_name[2] == '\0')))
-                               continue;
+               name_len = strlen(entry->d_name);
 
-               size_t name_len = strlen(entry->d_name);
+               if (should_ignore_filename(entry->d_name, name_len))
+                       continue;
 
-               path[path_len] = '/';
-               memcpy(&path[path_len + 1], entry->d_name, name_len + 1);
+               full_path[full_path_len] = '/';
+               memcpy(&full_path[full_path_len + 1], entry->d_name, name_len + 1);
                ret = unix_build_dentry_tree_recursive(&child,
-                                                      path,
-                                                      path_len + 1 + name_len,
+                                                      full_path,
+                                                      full_path_len + 1 + name_len,
+                                                      dirfd,
+                                                      &full_path[full_path_len + 1],
                                                       params);
+               full_path[full_path_len] = '\0';
                if (ret)
                        break;
-               if (child)
-                       dentry_add_child(dir_dentry, child);
+               attach_scanned_tree(dir_dentry, child, params->blob_table);
        }
-       path[path_len] = '\0';
        closedir(dir);
        return ret;
 }
 
-static int
-unix_capture_symlink(struct wim_dentry **root_p,
-                    const char *path,
-                    struct wim_inode *inode,
-                    struct add_image_params *params)
+/*
+ * Given an absolute symbolic link target (UNIX-style, beginning with '/'),
+ * determine whether it points into the directory identified by @ino and @dev.
+ * If yes, return the suffix of @target which is relative to this directory, but
+ * retaining leading slashes.  If no, return @target.
+ *
+ * Here are some examples, assuming that the @ino/@dev directory is "/home/e":
+ *
+ *     Original target         New target
+ *     ---------------         ----------
+ *     /home/e/test            /test
+ *     /home/e/test/           /test/
+ *     //home//e//test//       //test//
+ *     /home/e                                         (empty string)
+ *     /home/e/                /
+ *     /usr/lib                /usr/lib                (external link)
+ *
+ * Because of the possibility of other links into the @ino/@dev directory and/or
+ * multiple path separators, we can't simply do a string comparison; instead we
+ * need to stat() each ancestor directory.
+ *
+ * If the link points directly to the @ino/@dev directory with no trailing
+ * slashes, then the new target will be an empty string.  This is not a valid
+ * UNIX symlink target, but we store this in the archive anyway since the target
+ * is intended to be de-relativized when the link is extracted.
+ */
+static char *
+unix_relativize_link_target(char *target, u64 ino, u64 dev)
 {
-       char deref_name_buf[4096];
-       ssize_t deref_name_len;
-       int ret;
+       char *p = target;
 
-       inode->i_attributes = FILE_ATTRIBUTE_REPARSE_POINT;
-       inode->i_reparse_tag = WIM_IO_REPARSE_TAG_SYMLINK;
+       do {
+               char save;
+               struct stat stbuf;
+               int ret;
 
-       /* The idea here is to call readlink() to get the UNIX target of the
-        * symbolic link, then turn the target into a reparse point data buffer
-        * that contains a relative or absolute symbolic link. */
-       deref_name_len = readlink(path, deref_name_buf,
-                                 sizeof(deref_name_buf) - 1);
-       if (deref_name_len >= 0) {
-               char *dest = deref_name_buf;
+               /* Skip slashes (guaranteed to be at least one here)  */
+               do {
+                       p++;
+               } while (*p == '/');
 
-               dest[deref_name_len] = '\0';
-               DEBUG("Read symlink `%s'", dest);
+               /* End of string?  */
+               if (!*p)
+                       break;
 
-               if ((params->add_flags & WIMLIB_ADD_FLAG_RPFIX) &&
-                    dest[0] == '/')
-               {
-                       dest = capture_fixup_absolute_symlink(dest,
-                                                             params->capture_root_ino,
-                                                             params->capture_root_dev);
-                       if (dest == NULL) {
-                               /* RPFIX (reparse point fixup) mode:  Ignore
-                                * absolute symbolic link that points out of the
-                                * tree to be captured.  */
-                               free_dentry(*root_p);
-                               *root_p = NULL;
-                               params->progress.scan.cur_path = path;
-                               params->progress.scan.symlink_target = deref_name_buf;
-                               do_capture_progress(params,
-                                                   WIMLIB_SCAN_DENTRY_EXCLUDED_SYMLINK,
-                                                   NULL);
-                               return 0;
-                       }
-                       inode->i_not_rpfixed = 0;
+               /* Skip non-slashes (guaranteed to be at least one here)  */
+               do {
+                       p++;
+               } while (*p && *p != '/');
+
+               /* Get the inode and device numbers for this prefix.  */
+               save = *p;
+               *p = '\0';
+               ret = stat(target, &stbuf);
+               *p = save;
+
+               if (ret) {
+                       /* stat() failed.  Assume the link points outside the
+                        * directory tree being captured.  */
+                       break;
+               }
+
+               if (stbuf.st_ino == ino && stbuf.st_dev == dev) {
+                       /* Link points inside directory tree being captured.
+                        * Return abbreviated path.  */
+                       return p;
                }
-               ret = wim_inode_set_symlink(inode, dest, params->lookup_table);
-               if (ret == 0) {
-                       /* Unfortunately, Windows seems to have the concept of
-                        * "file" symbolic links as being different from
-                        * "directory" symbolic links...  so
-                        * FILE_ATTRIBUTE_DIRECTORY needs to be set on the
-                        * symbolic link if the *target* of the symbolic link is
-                        * a directory.  */
-                       struct stat stbuf;
-                       if (stat(path, &stbuf) == 0 && S_ISDIR(stbuf.st_mode))
-                               inode->i_attributes |= FILE_ATTRIBUTE_DIRECTORY;
+       } while (*p);
+
+       /* Link does not point inside directory tree being captured.  */
+       return target;
+}
+
+static noinline_for_stack int
+unix_scan_symlink(const char *full_path, int dirfd, const char *relpath,
+                 struct wim_inode *inode, struct capture_params *params)
+{
+       char orig_target[REPARSE_POINT_MAX_SIZE];
+       char *target = orig_target;
+       int ret;
+
+       /* Read the UNIX symbolic link target.  */
+       ret = my_readlinkat(full_path, dirfd, relpath, target,
+                           sizeof(orig_target));
+       if (unlikely(ret < 0)) {
+               ERROR_WITH_ERRNO("\"%s\": Can't read target of symbolic link",
+                                full_path);
+               return WIMLIB_ERR_READLINK;
+       }
+       if (unlikely(ret >= sizeof(orig_target))) {
+               ERROR("\"%s\": target of symbolic link is too long", full_path);
+               return WIMLIB_ERR_READLINK;
+       }
+       target[ret] = '\0';
+
+       /* If the link is absolute and reparse point fixups are enabled, then
+        * change it to be "absolute" relative to the tree being captured.  */
+       if (target[0] == '/' && (params->add_flags & WIMLIB_ADD_FLAG_RPFIX)) {
+               int status = WIMLIB_SCAN_DENTRY_NOT_FIXED_SYMLINK;
+
+               params->progress.scan.cur_path = full_path;
+               params->progress.scan.symlink_target = target;
+
+               target = unix_relativize_link_target(target,
+                                                    params->capture_root_ino,
+                                                    params->capture_root_dev);
+               if (target != orig_target) {
+                       /* Link target was fixed.  */
+                       inode->i_rp_flags &= ~WIM_RP_FLAG_NOT_FIXED;
+                       status = WIMLIB_SCAN_DENTRY_FIXED_SYMLINK;
                }
-       } else {
-               ERROR_WITH_ERRNO("Failed to read target of "
-                                "symbolic link `%s'", path);
-               ret = WIMLIB_ERR_READLINK;
+               ret = do_capture_progress(params, status, NULL);
+               if (ret)
+                       return ret;
        }
-       return ret;
+
+       /* Translate the UNIX symlink target into a Windows reparse point.  */
+       ret = wim_inode_set_symlink(inode, target, params->blob_table);
+       if (ret)
+               return ret;
+
+       /* On Windows, a reparse point can be set on both directory and
+        * non-directory files.  Usually, a link that is intended to point to a
+        * (non-)directory is stored as a reparse point on a (non-)directory
+        * file.  Replicate this behavior by examining the target file.  */
+       struct stat stbuf;
+       if (my_fstatat(full_path, dirfd, relpath, &stbuf, 0) == 0 &&
+           S_ISDIR(stbuf.st_mode))
+               inode->i_attributes |= FILE_ATTRIBUTE_DIRECTORY;
+       return 0;
 }
 
 static int
-unix_build_dentry_tree_recursive(struct wim_dentry **root_ret,
-                                char *path,
-                                size_t path_len,
-                                struct add_image_params *params)
+unix_build_dentry_tree_recursive(struct wim_dentry **tree_ret,
+                                char *full_path, size_t full_path_len,
+                                int dirfd, const char *relpath,
+                                struct capture_params *params)
 {
-       struct wim_dentry *root = NULL;
-       int ret;
+       struct wim_dentry *tree = NULL;
        struct wim_inode *inode = NULL;
+       int ret;
        struct stat stbuf;
+       int stat_flags;
 
-       if (exclude_path(path, path_len, params->config, true)) {
-               ret = 0;
+       ret = try_exclude(full_path, params);
+       if (unlikely(ret < 0)) /* Excluded? */
                goto out_progress;
-       }
+       if (unlikely(ret > 0)) /* Error? */
+               goto out;
 
-       if ((params->add_flags & WIMLIB_ADD_FLAG_DEREFERENCE) ||
-           (params->add_flags & WIMLIB_ADD_FLAG_ROOT))
-               ret = stat(path, &stbuf);
+       if (params->add_flags & (WIMLIB_ADD_FLAG_DEREFERENCE |
+                                WIMLIB_ADD_FLAG_ROOT))
+               stat_flags = 0;
        else
-               ret = lstat(path, &stbuf);
+               stat_flags = AT_SYMLINK_NOFOLLOW;
+
+       ret = my_fstatat(full_path, dirfd, relpath, &stbuf, stat_flags);
 
        if (ret) {
-               ERROR_WITH_ERRNO("Failed to stat \"%s\"", path);
+               ERROR_WITH_ERRNO("\"%s\": Can't read metadata", full_path);
                ret = WIMLIB_ERR_STAT;
                goto out;
        }
 
-       if (!S_ISREG(stbuf.st_mode) &&
-           !S_ISDIR(stbuf.st_mode) &&
-           !S_ISLNK(stbuf.st_mode))
-       {
-               if (params->add_flags & WIMLIB_ADD_FLAG_NO_UNSUPPORTED_EXCLUDE)
+       if (!(params->add_flags & WIMLIB_ADD_FLAG_UNIX_DATA)) {
+               if (unlikely(!S_ISREG(stbuf.st_mode) &&
+                            !S_ISDIR(stbuf.st_mode) &&
+                            !S_ISLNK(stbuf.st_mode)))
                {
-                       ERROR("Can't archive unsupported file \"%s\"", path);
-                       ret = WIMLIB_ERR_UNSUPPORTED_FILE;
+                       if (params->add_flags &
+                           WIMLIB_ADD_FLAG_NO_UNSUPPORTED_EXCLUDE)
+                       {
+                               ERROR("\"%s\": File type is unsupported",
+                                     full_path);
+                               ret = WIMLIB_ERR_UNSUPPORTED_FILE;
+                               goto out;
+                       }
+                       params->progress.scan.cur_path = full_path;
+                       ret = do_capture_progress(params,
+                                                 WIMLIB_SCAN_DENTRY_UNSUPPORTED,
+                                                 NULL);
                        goto out;
                }
-               params->progress.scan.cur_path = path;
-               do_capture_progress(params, WIMLIB_SCAN_DENTRY_UNSUPPORTED, NULL);
-               ret = 0;
-               goto out;
        }
 
-       ret = inode_table_new_dentry(&params->inode_table,
-                                    path_basename_with_len(path, path_len),
-                                    stbuf.st_ino, stbuf.st_dev, false, &root);
+       ret = inode_table_new_dentry(params->inode_table, relpath,
+                                    stbuf.st_ino, stbuf.st_dev, false, &tree);
        if (ret)
                goto out;
 
-       inode = root->d_inode;
+       inode = tree->d_inode;
 
-       if (inode->i_nlink > 1) {
-               /* Already captured this inode? */
-               ret = 0;
+       /* Already seen this inode?  */
+       if (inode->i_nlink > 1)
                goto out_progress;
-       }
 
 #ifdef HAVE_STAT_NANOSECOND_PRECISION
-       inode->i_creation_time = timespec_to_wim_timestamp(stbuf.st_mtim);
-       inode->i_last_write_time = timespec_to_wim_timestamp(stbuf.st_mtim);
-       inode->i_last_access_time = timespec_to_wim_timestamp(stbuf.st_atim);
+       inode->i_creation_time = timespec_to_wim_timestamp(&stbuf.st_mtim);
+       inode->i_last_write_time = timespec_to_wim_timestamp(&stbuf.st_mtim);
+       inode->i_last_access_time = timespec_to_wim_timestamp(&stbuf.st_atim);
 #else
-       inode->i_creation_time = unix_timestamp_to_wim(stbuf.st_mtime);
-       inode->i_last_write_time = unix_timestamp_to_wim(stbuf.st_mtime);
-       inode->i_last_access_time = unix_timestamp_to_wim(stbuf.st_atime);
+       inode->i_creation_time = time_t_to_wim_timestamp(stbuf.st_mtime);
+       inode->i_last_write_time = time_t_to_wim_timestamp(stbuf.st_mtime);
+       inode->i_last_access_time = time_t_to_wim_timestamp(stbuf.st_atime);
 #endif
-       inode->i_resolved = 1;
        if (params->add_flags & WIMLIB_ADD_FLAG_UNIX_DATA) {
-               ret = inode_set_unix_data(inode, stbuf.st_uid,
-                                         stbuf.st_gid,
-                                         stbuf.st_mode,
-                                         params->lookup_table,
-                                         UNIX_DATA_ALL | UNIX_DATA_CREATE);
-               if (ret)
+               struct wimlib_unix_data unix_data;
+
+               unix_data.uid = stbuf.st_uid;
+               unix_data.gid = stbuf.st_gid;
+               unix_data.mode = stbuf.st_mode;
+               unix_data.rdev = stbuf.st_rdev;
+               if (!inode_set_unix_data(inode, &unix_data, UNIX_DATA_ALL)) {
+                       ret = WIMLIB_ERR_NOMEM;
                        goto out;
+               }
        }
-       params->add_flags &= ~WIMLIB_ADD_FLAG_ROOT;
-       if (S_ISREG(stbuf.st_mode))
-               ret = unix_capture_regular_file(path, stbuf.st_size,
-                                               inode, params->unhashed_streams);
-       else if (S_ISDIR(stbuf.st_mode))
-               ret = unix_capture_directory(root, path, path_len, params);
-       else {
-               ret = unix_capture_symlink(&root, path, inode, params);
-               if (root == NULL)
-                       goto out;
+
+       if (params->add_flags & WIMLIB_ADD_FLAG_ROOT) {
+               params->capture_root_ino = stbuf.st_ino;
+               params->capture_root_dev = stbuf.st_dev;
+               params->add_flags &= ~WIMLIB_ADD_FLAG_ROOT;
+       }
+
+       if (S_ISREG(stbuf.st_mode)) {
+               ret = unix_scan_regular_file(full_path, stbuf.st_size,
+                                            inode, params->unhashed_blobs);
+       } else if (S_ISDIR(stbuf.st_mode)) {
+               ret = unix_scan_directory(tree, full_path, full_path_len,
+                                         dirfd, relpath, params);
+       } else if (S_ISLNK(stbuf.st_mode)) {
+               ret = unix_scan_symlink(full_path, dirfd, relpath,
+                                       inode, params);
        }
 
        if (ret)
                goto out;
 
 out_progress:
-       params->progress.scan.cur_path = path;
-       if (root == NULL)
-               do_capture_progress(params, WIMLIB_SCAN_DENTRY_EXCLUDED, NULL);
+       params->progress.scan.cur_path = full_path;
+       if (likely(tree))
+               ret = do_capture_progress(params, WIMLIB_SCAN_DENTRY_OK, inode);
        else
-               do_capture_progress(params, WIMLIB_SCAN_DENTRY_OK, inode);
+               ret = do_capture_progress(params, WIMLIB_SCAN_DENTRY_EXCLUDED, NULL);
 out:
-       if (ret)
-               free_dentry_tree(root, params->lookup_table);
-       else
-               *root_ret = root;
+       if (unlikely(ret)) {
+               free_dentry_tree(tree, params->blob_table);
+               tree = NULL;
+               ret = report_capture_error(params, ret, full_path);
+       }
+       *tree_ret = tree;
        return ret;
 }
 
@@ -315,7 +467,7 @@ out:
  *
  * @root_disk_path:  The path to the root of the directory tree on disk.
  *
- * @params:     See doc for `struct add_image_params'.
+ * @params:     See doc for `struct capture_params'.
  *
  * @return:    0 on success, nonzero on failure.  It is a failure if any of
  *             the files cannot be `stat'ed, or if any of the needed
@@ -327,33 +479,15 @@ out:
 int
 unix_build_dentry_tree(struct wim_dentry **root_ret,
                       const char *root_disk_path,
-                      struct add_image_params *params)
+                      struct capture_params *params)
 {
-       char *path_buf;
-       int ret;
        size_t path_len;
        size_t path_bufsz;
+       char *path_buf;
+       int ret;
 
-       {
-               struct stat root_stbuf;
-               if (stat(root_disk_path, &root_stbuf)) {
-                       ERROR_WITH_ERRNO("Failed to stat \"%s\"", root_disk_path);
-                       return WIMLIB_ERR_STAT;
-               }
-
-               if ((params->add_flags & WIMLIB_ADD_FLAG_ROOT) &&
-                   !S_ISDIR(root_stbuf.st_mode))
-               {
-                       ERROR("Root of capture \"%s\" is not a directory",
-                             root_disk_path);
-                       return WIMLIB_ERR_NOTDIR;
-               }
-               params->capture_root_ino = root_stbuf.st_ino;
-               params->capture_root_dev = root_stbuf.st_dev;
-       }
-
-       path_bufsz = min(32790, PATH_MAX + 1);
        path_len = strlen(root_disk_path);
+       path_bufsz = min(32790, PATH_MAX + 1);
 
        if (path_len >= path_bufsz)
                return WIMLIB_ERR_INVALID_PARAM;
@@ -363,8 +497,10 @@ unix_build_dentry_tree(struct wim_dentry **root_ret,
                return WIMLIB_ERR_NOMEM;
        memcpy(path_buf, root_disk_path, path_len + 1);
 
-       ret = unix_build_dentry_tree_recursive(root_ret, path_buf,
-                                              path_len, params);
+       params->capture_root_nchars = path_len;
+
+       ret = unix_build_dentry_tree_recursive(root_ret, path_buf, path_len,
+                                              AT_FDCWD, path_buf, params);
        FREE(path_buf);
        return ret;
 }