]> wimlib.net Git - wimlib/blobdiff - src/resource.c
wimfs_write(), dentry_to_stbuf()
[wimlib] / src / resource.c
index bd28ffc9d8d396451955ad87657a174b21f6881e..48f54804576a3d68fdb25d308fe4d8d26dc61e01 100644 (file)
@@ -2,24 +2,26 @@
  * resource.c
  *
  * Read uncompressed and compressed metadata and file resources.
- *
+ */
+
+/*
  * Copyright (C) 2010 Carl Thijssen
  * Copyright (C) 2012 Eric Biggers
  *
- * wimlib - Library for working with WIM files
+ * This file is part of wimlib, a library for working with WIM files.
  *
- * This library 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 2.1 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 Lesser General Public License as published by the Free
+ * Software Foundation; either version 2.1 of the License, or (at your option)
+ * any later version.
  *
- * This library 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.
+ * 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 Lesser General Public License for more
+ * details.
  *
- * You should have received a copy of the GNU Lesser General Public License along
- * with this library; if not, write to the Free Software Foundation, Inc., 59
- * Temple Place, Suite 330, Boston, MA 02111-1307 USA 
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with wimlib; if not, see http://www.gnu.org/licenses/.
  */
 
 #include "wimlib_internal.h"
@@ -29,6 +31,7 @@
 #include "xpress.h"
 #include "sha1.h"
 #include "dentry.h"
+#include "config.h"
 #include <unistd.h>
 #include <errno.h>
 
@@ -57,15 +60,13 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size,
                                    u64 len, u64 offset, u8  contents_ret[])
 {
 
-       DEBUG2("comp size = %"PRIu64", "
-                       "uncomp size = %"PRIu64", "
-                       "res offset = %"PRIu64"\n",
-                       resource_compressed_size,
-                       resource_uncompressed_size,
-                       resource_offset);
-       DEBUG2("resource_ctype = %s, len = %"PRIu64", offset = %"PRIu64"\n",
-                               wimlib_get_compression_type_string(resource_ctype), 
-                                                               len, offset);
+       DEBUG2("comp size = %"PRIu64", uncomp size = %"PRIu64", "
+              "res offset = %"PRIu64"",
+              resource_compressed_size,
+              resource_uncompressed_size,
+              resource_offset);
+       DEBUG2("resource_ctype = %s, len = %"PRIu64", offset = %"PRIu64"",
+              wimlib_get_compression_type_string(resource_ctype), len, offset);
        /* Trivial case */
        if (len == 0)
                return 0;
@@ -155,10 +156,9 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size,
        u64 file_offset_of_needed_chunk_entries = resource_offset + 
                                start_table_idx * chunk_entry_size;
        if (fseeko(fp, file_offset_of_needed_chunk_entries, SEEK_SET) != 0) {
-               ERROR("Failed to seek to byte %"PRIu64" "
-                               "to read chunk table of compressed "
-                               "resource: %m\n", 
-                               file_offset_of_needed_chunk_entries);
+               ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" to read "
+                                "chunk table of compressed resource",
+                                file_offset_of_needed_chunk_entries);
                return WIMLIB_ERR_READ;
        }
 
@@ -193,10 +193,9 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size,
        u64 file_offset_of_first_needed_chunk = resource_offset + 
                                chunk_table_size + chunk_offsets[0];
        if (fseeko(fp, file_offset_of_first_needed_chunk, SEEK_SET) != 0) {
-               ERROR("Failed to seek to byte %"PRIu64" "
-                               "to read first chunk of compressed "
-                               "resource: %m\n", 
-                               file_offset_of_first_needed_chunk);
+               ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" to read "
+                                "first chunk of compressed resource",
+                                file_offset_of_first_needed_chunk);
                return WIMLIB_ERR_READ;
        }
 
@@ -216,8 +215,8 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size,
        /* Decompress all the chunks. */
        for (u64 i = start_chunk; i <= end_chunk; i++) {
 
-               DEBUG2("Chunk %"PRIu64" (start %"PRIu64", end %"PRIu64")\n",
-                               i, start_chunk, end_chunk);
+               DEBUG2("Chunk %"PRIu64" (start %"PRIu64", end %"PRIu64").",
+                      i, start_chunk, end_chunk);
 
                /* Calculate the sizes of the compressed chunk and of the
                 * uncompressed chunk. */
@@ -252,8 +251,9 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size,
                                uncompressed_chunk_size = WIM_CHUNK_SIZE;
                }
 
-               DEBUG2("compressed_chunk_size = %u, uncompressed_chunk_size = %u\n",
-                               compressed_chunk_size, uncompressed_chunk_size);
+               DEBUG2("compressed_chunk_size = %u, "
+                      "uncompressed_chunk_size = %u",
+                      compressed_chunk_size, uncompressed_chunk_size);
 
 
                /* Figure out how much of this chunk we actually need to read */
@@ -272,9 +272,9 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size,
                bool is_partial_chunk = (partial_chunk_size != 
                                                uncompressed_chunk_size);
 
-               DEBUG2("start_offset = %u, end_offset = %u\n", start_offset,
+               DEBUG2("start_offset = %u, end_offset = %u", start_offset,
                                        end_offset);
-               DEBUG2("partial_chunk_size = %u\n", partial_chunk_size);
+               DEBUG2("partial_chunk_size = %u", partial_chunk_size);
 
                /* This is undocumented, but chunks can be uncompressed.  This
                 * appears to always be the case when the compressed chunk size
@@ -284,8 +284,8 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size,
 
                        if (start_offset != 0) {
                                if (fseeko(fp, start_offset, SEEK_CUR) != 0) {
-                                       ERROR("Uncompressed partial chunk "
-                                                       "fseek() error: %m\n");
+                                       ERROR_WITH_ERRNO("Uncompressed partial "
+                                                        "chunk fseek() error");
                                        return WIMLIB_ERR_READ;
                                }
                        }
@@ -315,7 +315,6 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size,
                                memcpy(out_p, uncompressed_buf + start_offset,
                                                partial_chunk_size);
                        } else {
-                               DEBUG2("out_p = %p\n");
                                ret = decompress(compressed_buf,
                                                compressed_chunk_size,
                                                out_p,
@@ -334,9 +333,9 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size,
 
 err:
        if (feof(fp))
-               ERROR("Unexpected EOF in compressed file resource\n");
+               ERROR("Unexpected EOF in compressed file resource");
        else
-               ERROR("Error reading compressed file resource: %m\n");
+               ERROR_WITH_ERRNO("Error reading compressed file resource");
        return WIMLIB_ERR_READ;
 }
 
@@ -348,17 +347,17 @@ int read_uncompressed_resource(FILE *fp, u64 offset, u64 len,
 {
        if (fseeko(fp, offset, SEEK_SET) != 0) {
                ERROR("Failed to seek to byte %"PRIu64" of input file "
-                               "to read uncompressed resource "
-                               "(len = %"PRIu64")!\n", offset, len);
+                     "to read uncompressed resource (len = %"PRIu64")",
+                     offset, len);
                return WIMLIB_ERR_READ;
        }
        if (fread(contents_ret, 1, len, fp) != len) {
                if (feof(fp)) {
-                       ERROR("Unexpected EOF in uncompressed file resource!\n");
+                       ERROR("Unexpected EOF in uncompressed file resource");
                } else {
                        ERROR("Failed to read %"PRIu64" bytes from "
-                                       "uncompressed resource at offset "
-                                       "%"PRIu64"\n", len, offset);
+                             "uncompressed resource at offset %"PRIu64,
+                             len, offset);
                }
                return WIMLIB_ERR_READ;
        }
@@ -400,12 +399,10 @@ int read_resource(FILE *fp, u64 resource_size, u64 resource_original_size,
 {
        if (resource_ctype == WIM_COMPRESSION_TYPE_NONE) {
                if (resource_size != resource_original_size) {
-                       ERROR("Resource with original size %"PRIu64" "
-                                       "bytes is marked as uncompressed, \n",
-                                       resource_original_size);
-                       ERROR("    but its actual size is %"PRIu64" "
-                                                               "bytes!\n",
-                                       resource_size);
+                       ERROR("Resource with original size %"PRIu64" bytes is "
+                             "marked as uncompressed, but its actual size is "
+                             "%"PRIu64" bytes", 
+                             resource_original_size, resource_size);
                        return WIMLIB_ERR_INVALID_RESOURCE_SIZE;
                }
                return read_uncompressed_resource(fp, 
@@ -540,14 +537,11 @@ u8 *put_resource_entry(u8 *p, const struct resource_entry *entry)
  * a resource entry, returns the compression type for that resource entry. */
 int resource_compression_type(int wim_ctype, int reshdr_flags)
 {
-       if (wim_ctype == WIM_COMPRESSION_TYPE_NONE) {
+       if (wim_ctype != WIM_COMPRESSION_TYPE_NONE &&
+            (reshdr_flags & WIM_RESHDR_FLAG_COMPRESSED))
+               return wim_ctype;
+       else
                return WIM_COMPRESSION_TYPE_NONE;
-       } else {
-               if (reshdr_flags & WIM_RESHDR_FLAG_COMPRESSED)
-                       return wim_ctype;
-               else
-                       return WIM_COMPRESSION_TYPE_NONE;
-       }
 }
 
 
@@ -555,35 +549,36 @@ int resource_compression_type(int wim_ctype, int reshdr_flags)
 /*
  * Copies bytes between two file streams.
  *
- * Copies @len bytes from @in to @out, at the current position in @out, and at
- * an offset of @in_offset in @in.
+ * Copies @len bytes from @in_fp to @out_fp, at the current position in @out_fp,
+ * and at an offset of @in_offset in @in_fp.
  */
-int copy_between_files(FILE *in, off_t in_offset, FILE *out, size_t len)
+int copy_between_files(FILE *in_fp, off_t in_offset, FILE *out_fp, size_t len)
 {
        u8 buf[BUFFER_SIZE];
        size_t n;
 
-       if (fseeko(in, in_offset, SEEK_SET) != 0) {
-               ERROR("Failed to seek to byte %"PRIu64" of input file: %m\n",
-                               in_offset);
+       if (fseeko(in_fp, in_offset, SEEK_SET) != 0) {
+               ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" of "
+                                "input file", in_offset);
                return WIMLIB_ERR_READ;
        }
        /* To reduce memory usage and improve speed, read and write BUFFER_SIZE
         * bytes at a time. */
        while (len != 0) {
                n = min(len, BUFFER_SIZE);
-               if (fread(buf, 1, n, in) != n) {
-                       if (feof(in)) {
+               if (fread(buf, 1, n, in_fp) != n) {
+                       if (feof(in_fp)) {
                                ERROR("Unexpected EOF when copying data "
-                                               "between files\n");
+                                     "between files");
                        } else {
-                               ERROR("Error copying data between files: %m\n");
+                               ERROR_WITH_ERRNO("Error copying data between "
+                                                "files");
                        }
                        return WIMLIB_ERR_READ;
                }
 
-               if (fwrite(buf, 1, n, out) != n) {
-                       ERROR("Error copying data between files: %m\n");
+               if (fwrite(buf, 1, n, out_fp) != n) {
+                       ERROR_WITH_ERRNO("Error copying data between files");
                        return WIMLIB_ERR_WRITE;
                }
                len -= n;
@@ -595,15 +590,15 @@ int copy_between_files(FILE *in, off_t in_offset, FILE *out, size_t len)
 /* 
  * Uncompresses a WIM file resource and writes it uncompressed to a file stream.
  *
- * @in:                    The file stream that contains the file resource.
+ * @in_fp:          The file stream that contains the file resource.
  * @size:           The size of the resource in the input file.
  * @original_size:  The original (uncompressed) size of the resource. 
  * @offset:        The offset of the start of the resource in @in.
  * @input_ctype:    The compression type of the resource in @in.
- * @out:           The file stream to write the file resource to.
+ * @out_fp:        The file stream to write the file resource to.
  */
-static int uncompress_resource(FILE *in, u64 size, u64 original_size,
-                              off_t offset, int input_ctype, FILE *out)
+static int uncompress_resource(FILE *in_fp, u64 size, u64 original_size,
+                              off_t offset, int input_ctype, FILE *out_fp)
 {
        int ret;
        u8 buf[WIM_CHUNK_SIZE];
@@ -618,18 +613,19 @@ static int uncompress_resource(FILE *in, u64 size, u64 original_size,
        for (i = 0; i < num_chunks; i++) {
 
                uncompressed_offset = i * WIM_CHUNK_SIZE;
-               uncompressed_chunk_size = min(WIM_CHUNK_SIZE, 
-                                       original_size - uncompressed_offset);
+               uncompressed_chunk_size = min(WIM_CHUNK_SIZE, original_size -
+                                             uncompressed_offset);
 
-               ret = read_resource(in, size, original_size, offset, input_ctype, 
-                                       uncompressed_chunk_size, 
-                                       uncompressed_offset, buf);
+               ret = read_resource(in_fp, size, original_size, offset,
+                                   input_ctype, uncompressed_chunk_size, 
+                                   uncompressed_offset, buf);
                if (ret != 0)
                        return ret;
 
-               if (fwrite(buf, 1, uncompressed_chunk_size, out) != 
-                                               uncompressed_chunk_size) {
-                       ERROR("Failed to write file resource: %m\n");
+               if (fwrite(buf, 1, uncompressed_chunk_size, out_fp) != 
+                     uncompressed_chunk_size) 
+               {
+                       ERROR_WITH_ERRNO("Failed to write file resource");
                        return WIMLIB_ERR_WRITE;
                }
        }
@@ -642,7 +638,7 @@ static int uncompress_resource(FILE *in, u64 size, u64 original_size,
  * Alternatively, the input resource may be in-memory, but it must be
  * uncompressed.
  *
- * @in:                    The file stream that contains the file resource.  Ignored
+ * @in_fp:                 The file stream that contains the file resource.  Ignored
  *                     if uncompressed_resource != NULL.
  * @uncompressed_resource:     If this pointer is not NULL, it points to an
  *                                     array of @original_size bytes that are
@@ -653,16 +649,16 @@ static int uncompress_resource(FILE *in, u64 size, u64 original_size,
  *                     if uncompressed_resource != NULL.
  * @input_ctype:    The compression type of the resource in @in.  Ignored if
  *                     uncompressed_resource != NULL.
- * @out:           The file stream to write the file resource to.
+ * @out_fp:        The file stream to write the file resource to.
  * @output_type:    The compression type to use when writing the resource to
  *                     @out.
  * @new_size_ret:   A location into which the new compressed size of the file
  *                     resource in returned.
  */
-static int recompress_resource(FILE *in, const u8 *uncompressed_resource, 
-                                       u64 size, u64 original_size,
-                                       off_t offset, int input_ctype, FILE *out,
-                                       int output_ctype, u64 *new_size_ret)
+static int recompress_resource(FILE *in_fp, const u8 *uncompressed_resource, 
+                              u64 size, u64 original_size,
+                              off_t offset, int input_ctype, FILE *out_fp,
+                              int output_ctype, u64 *new_size_ret)
 {
        int ret;
        int (*compress)(const void *, uint, void *, uint *);
@@ -682,20 +678,27 @@ static int recompress_resource(FILE *in, const u8 *uncompressed_resource,
 
        /* Size of the chunk entries--- 8 bytes for files over 4GB, otherwise 4
         * bytes */
-       uint chunk_entry_size = (original_size >= (u64)1 << 32) ?  8 : 4;
+       uint chunk_entry_size = (original_size >= (u64)1 << 32) ? 8 : 4;
 
        /* Array in which to construct the chunk offset table. */
        u64 chunk_offsets[num_chunk_entries];
 
        /* Offset of the start of the chunk table in the output file. */
-       off_t chunk_tab_offset = ftello(out);
+       off_t chunk_tab_offset = ftello(out_fp);
+
+       if (chunk_tab_offset == -1) {
+               ERROR_WITH_ERRNO("Failed to get offset of output file");
+               return WIMLIB_ERR_WRITE;
+       }
 
        /* Total size of the chunk table (as written to the file) */
        u64 chunk_tab_size = chunk_entry_size * num_chunk_entries;
 
        /* Reserve space for the chunk table. */
-       if (fwrite(chunk_offsets, 1, chunk_tab_size, out) != chunk_tab_size) {
-               ERROR("Failed to write chunk offset table: %m\n");
+       if (fwrite(chunk_offsets, 1, chunk_tab_size, out_fp) !=
+             chunk_tab_size)
+       {
+               ERROR_WITH_ERRNO("Failed to write chunk offset table");
                return WIMLIB_ERR_WRITE;
        }
 
@@ -711,14 +714,15 @@ static int recompress_resource(FILE *in, const u8 *uncompressed_resource,
                const u8 *uncompressed_p;
                if (uncompressed_resource != NULL) {
                        uncompressed_p = uncompressed_resource + 
-                                                       uncompressed_offset;
+                                        uncompressed_offset;
 
                } else {
                        /* Read chunk i of the file into uncompressed_buf. */
-                       ret = read_resource(in, size, original_size, offset, input_ctype, 
-                                               uncompressed_chunk_size, 
-                                               uncompressed_offset, 
-                                               uncompressed_buf);
+                       ret = read_resource(in_fp, size, original_size, offset,
+                                           input_ctype,
+                                           uncompressed_chunk_size, 
+                                           uncompressed_offset, 
+                                           uncompressed_buf);
                        if (ret != 0)
                                return ret;
                        uncompressed_p = uncompressed_buf;
@@ -746,8 +750,11 @@ static int recompress_resource(FILE *in, const u8 *uncompressed_resource,
                        len_to_write = uncompressed_chunk_size;
                }
 
-               if (fwrite(buf_to_write, 1, len_to_write, out) != len_to_write) {
-                       ERROR("Failed to write compressed file resource: %m\n");
+               if (fwrite(buf_to_write, 1, len_to_write, out_fp) !=
+                     len_to_write)
+               {
+                       ERROR_WITH_ERRNO("Failed to write compressed "
+                                        "file resource");
                        return WIMLIB_ERR_WRITE;
                }
                cur_chunk_offset += len_to_write;
@@ -760,32 +767,25 @@ static int recompress_resource(FILE *in, const u8 *uncompressed_resource,
        /* Now that all entries of the chunk table are determined, rewind the
         * stream to where the chunk table was, and write it back out. */
 
-       if (fseeko(out, chunk_tab_offset, SEEK_SET) != 0) {
-               ERROR("Failed to seek to beginning of chunk table: %m\n");
+       if (fseeko(out_fp, chunk_tab_offset, SEEK_SET) != 0) {
+               ERROR_WITH_ERRNO("Failed to seek to beginning of chunk table");
                return WIMLIB_ERR_READ;
        }
 
        if (chunk_entry_size == 8) {
                array_to_le64(chunk_offsets, num_chunk_entries);
-
-               if (fwrite(chunk_offsets, 1, chunk_tab_size, out) != 
-                               chunk_tab_size) {
-                       ERROR("Failed to write chunk table: %m\n");
-                       return WIMLIB_ERR_WRITE;
-               }
        } else {
-               u32 chunk_entries_small[num_chunk_entries];
                for (u64 i = 0; i < num_chunk_entries; i++)
-                       chunk_entries_small[i] = to_le32(chunk_offsets[i]);
-               if (fwrite(chunk_entries_small, 1, chunk_tab_size, out) != 
-                               chunk_tab_size) {
-                       ERROR("Failed to write chunk table: %m\n");
-                       return WIMLIB_ERR_WRITE;
-               }
+                       ((u32*)chunk_offsets)[i] = to_le32(chunk_offsets[i]);
+       }
+       if (fwrite(chunk_offsets, 1, chunk_tab_size, out_fp) != chunk_tab_size)
+       {
+               ERROR_WITH_ERRNO("Failed to write chunk table");
+               return WIMLIB_ERR_WRITE;
        }
 
-       if (fseeko(out, 0, SEEK_END) != 0) {
-               ERROR("Failed to seek to end of output file: %m\n");
+       if (fseeko(out_fp, 0, SEEK_END) != 0) {
+               ERROR_WITH_ERRNO("Failed to seek to end of output file");
                return WIMLIB_ERR_WRITE;
        }
 
@@ -793,23 +793,24 @@ static int recompress_resource(FILE *in, const u8 *uncompressed_resource,
 }
 
 int write_resource_from_memory(const u8 resource[], int out_ctype,
-                              u64 resource_original_size, FILE *out,
+                              u64 resource_original_size, FILE *out_fp,
                               u64 *resource_size_ret)
 {
        if (out_ctype == WIM_COMPRESSION_TYPE_NONE) {
-               if (fwrite(resource, 1, resource_original_size, out) != 
-                                       resource_original_size) {
-                       ERROR("Failed to write resource of length "
-                                       "%"PRIu64": %m\n", 
-                                       resource_original_size);
+               if (fwrite(resource, 1, resource_original_size, out_fp) != 
+                     resource_original_size)
+               {
+                       ERROR_WITH_ERRNO("Failed to write resource of length "
+                                        "%"PRIu64, resource_original_size);
                        return WIMLIB_ERR_WRITE;
                }
                *resource_size_ret = resource_original_size;
                return 0;
        } else {
-               return recompress_resource(NULL, resource, resource_original_size,
-                               resource_original_size, 0, 0, out, out_ctype, 
-                                                       resource_size_ret);
+               return recompress_resource(NULL, resource,
+                                          resource_original_size,
+                                          resource_original_size, 0, 0, out_fp,
+                                          out_ctype, resource_size_ret);
        }
 }
 
@@ -818,13 +819,13 @@ int write_resource_from_memory(const u8 resource[], int out_ctype,
  * Transfers a file resource from a FILE* opened for reading to a FILE* opened
  * for writing, possibly changing the compression type. 
  *
- * @in:                        The FILE* that contains the file resource.
+ * @in_fp:             The FILE* that contains the file resource.
  * @size:              The (compressed) size of the file resource.
  * @original_size:     The uncompressed size of the file resource.
  * @offset:            The offset of the file resource in the input file.
  * @input_ctype:       The compression type of the file resource in the input
  *                             file.
- * @out:               The FILE* for the output file.  The file resource is 
+ * @out_fp:            The FILE* for the output file.  The file resource is 
  *                             written at the current position of @out.
  * @output_ctype:      The compression type to which the file resource will be
  *                             converted.
@@ -834,9 +835,9 @@ int write_resource_from_memory(const u8 resource[], int out_ctype,
  *                             in for the file resource written to the output
  *                             file.
  */
-static int transfer_file_resource(FILE *in, u64 size, u64 original_size, 
-                                 off_t offset, int input_ctype, FILE *out
-                                 int output_ctype, 
+static int transfer_file_resource(FILE *in_fp, u64 size, u64 original_size,
+                                 off_t offset, int input_ctype, FILE *out_fp,
+                                 int output_ctype,
                                  struct resource_entry *output_res_entry)
 {
        int ret;
@@ -848,16 +849,17 @@ static int transfer_file_resource(FILE *in, u64 size, u64 original_size,
        }
 
        /* Get current offset in the output file. */
-       output_res_entry->offset = ftello(out);
-       if (output_res_entry->offset == -1) {
-               ERROR("Failed to get output position: %m\n");
+       off_t out_offset = ftello(out_fp);
+       if (out_offset == -1) {
+               ERROR_WITH_ERRNO("Failed to get output position");
                return WIMLIB_ERR_WRITE;
        }
+       output_res_entry->offset = (u64)out_offset;
 
        if (output_ctype == input_ctype) {
                /* The same compression types; simply copy the resource. */
 
-               ret = copy_between_files(in, offset, out, size);
+               ret = copy_between_files(in_fp, offset, out_fp, size);
                if (ret != 0)
                        return ret;
                output_res_entry->size = size;
@@ -866,9 +868,9 @@ static int transfer_file_resource(FILE *in, u64 size, u64 original_size,
 
                if (output_ctype == WIM_COMPRESSION_TYPE_NONE) {
                        /* Uncompress a compressed file resource */
-                       ret = uncompress_resource(in, size,
-                                               original_size, offset, 
-                                               input_ctype, out);
+                       ret = uncompress_resource(in_fp, size,
+                                                 original_size, offset, 
+                                                 input_ctype, out_fp);
                        if (ret != 0)
                                return ret;
                        output_res_entry->size = original_size;
@@ -877,9 +879,10 @@ static int transfer_file_resource(FILE *in, u64 size, u64 original_size,
                        /* Compress an uncompressed file resource, or compress a
                         * compressed file resource using a different
                         * compression type */
-                       ret = recompress_resource(in, NULL, size, original_size,
-                                               offset, input_ctype, out, 
-                                               output_ctype, &new_size);
+                       ret = recompress_resource(in_fp, NULL, size,
+                                                 original_size,
+                                                 offset, input_ctype, out_fp,
+                                                 output_ctype, &new_size);
                        if (ret != 0)
                                return ret;
                        output_res_entry->size = new_size;
@@ -905,29 +908,33 @@ static int transfer_file_resource(FILE *in, u64 size, u64 original_size,
  * length 8, because that's how long the 'length' field is.
  *
  * @fp:                The FILE* for the input WIM file.
- * @res_entry: The resource entry for the metadata resource (a.k.a the metadata
- *                     for the metadata)
  * @wim_ctype: The compression type of the WIM file.
- * @root_dentry_p:     A pointer to a pointer to a struct dentry structure into which the 
- *             root dentry is allocated and returned.
+ * @imd:       Pointer to the image metadata structure.  Its
+ *             `lookup_table_entry' member specifies the lookup table entry for
+ *             the metadata resource.  The rest of the image metadata entry
+ *             will be filled in by this function.
  *
- * @return:    True on success, false on failure.
+ * @return:    Zero on success, nonzero on failure.
  */
-int read_metadata_resource(FILE *fp, const struct resource_entry *res_entry,
-                          int wim_ctype, struct image_metadata *image_metadata)
+int read_metadata_resource(FILE *fp, int wim_ctype, struct image_metadata *imd)
 {
        u8 *buf;
        int ctype;
        u32 dentry_offset;
        int ret;
-       struct dentry *dentry = NULL;
+       const struct resource_entry *res_entry;
+       struct dentry *dentry;
+       struct wim_security_data *sd;
+       struct link_group_table *lgt;
+
+       res_entry = &imd->metadata_lte->resource_entry;
 
-       DEBUG("Reading metadata resource: length = %lu, offset = %lu\n",
-                       res_entry->original_size, res_entry->offset);
+       DEBUG("Reading metadata resource: length = %"PRIu64", "
+             "offset = %"PRIu64"",
+             res_entry->original_size, res_entry->offset);
 
        if (res_entry->original_size < 8) {
-               ERROR("Expected at least 8 bytes for the metadata "
-                               "resource!\n");
+               ERROR("Expected at least 8 bytes for the metadata resource");
                return WIMLIB_ERR_INVALID_RESOURCE_SIZE;
        }
 
@@ -936,8 +943,7 @@ int read_metadata_resource(FILE *fp, const struct resource_entry *res_entry,
 
        if (!buf) {
                ERROR("Failed to allocate %"PRIu64" bytes for uncompressed "
-                               "metadata resource!\n",
-                               res_entry->original_size);
+                     "metadata resource", res_entry->original_size);
                return WIMLIB_ERR_NOMEM;
        }
 
@@ -949,62 +955,79 @@ int read_metadata_resource(FILE *fp, const struct resource_entry *res_entry,
                                 res_entry->original_size, res_entry->offset, 
                                 ctype, buf);
        if (ret != 0)
-               goto err1;
+               goto out_free_buf;
 
-       DEBUG("Finished reading metadata resource into memory.\n");
+       DEBUG("Finished reading metadata resource into memory.");
 
+       /* The root directory entry starts after security data, on an 8-byte
+        * aligned address. 
+        *
+        * The security data starts with a 4-byte integer giving its total
+        * length. */
+
+       /* Read the security data into a wim_security_data structure. */
+       ret = read_security_data(buf, res_entry->original_size, &sd);
+       if (ret != 0)
+               goto out_free_buf;
 
        dentry = MALLOC(sizeof(struct dentry));
        if (!dentry) {
-               ERROR("Failed to allocate %zu bytes for root dentry!\n",
-                               sizeof(struct dentry));
+               ERROR("Failed to allocate %zu bytes for root dentry",
+                     sizeof(struct dentry));
                ret = WIMLIB_ERR_NOMEM;
-               goto err1;
+               goto out_free_security_data;
        }
 
-       /* Read the root directory entry starts after security data, on an
-        * 8-byte aligned address. 
-        *
-        * The security data starts with a 4-byte integer giving its total
-        * length. */
-
-       /* Read the security data into a WIMSecurityData structure. */
-#ifdef ENABLE_SECURITY_DATA
-       ret = read_security_data(buf, res_entry->original_size, 
-                                &image_metadata->security_data);
-       if (ret != 0)
-               goto err1;
-#endif
        get_u32(buf, &dentry_offset);
        if (dentry_offset == 0)
                dentry_offset = 8;
-       dentry_offset += (8 - dentry_offset % 8) % 8;
+       dentry_offset = (dentry_offset + 7) & ~7;
                
        ret = read_dentry(buf, res_entry->original_size, dentry_offset, dentry);
-       if (ret != 0)
-               goto err1;
-
        /* This is the root dentry, so set its pointers correctly. */
        dentry->parent = dentry;
        dentry->next   = dentry;
        dentry->prev   = dentry;
+       if (ret != 0)
+               goto out_free_dentry_tree;
 
+       DEBUG("Reading dentry tree");
        /* Now read the entire directory entry tree. */
        ret = read_dentry_tree(buf, res_entry->original_size, dentry);
        if (ret != 0)
-               goto err2;
+               goto out_free_dentry_tree;
 
+       DEBUG("Calculating dentry full paths");
        /* Calculate the full paths in the dentry tree. */
        ret = for_dentry_in_tree(dentry, calculate_dentry_full_path, NULL);
        if (ret != 0)
-               goto err2;
+               goto out_free_dentry_tree;
 
-       image_metadata->root_dentry = dentry;
-       FREE(buf);
-       return ret;
-err2:
+       DEBUG("Building link group table");
+       lgt = new_link_group_table(9001);
+       if (!lgt)
+               goto out_free_dentry_tree;
+       ret = for_dentry_in_tree(dentry, link_group_table_insert, lgt);
+       if (ret != 0)
+               goto out_free_lgt;
+
+       DEBUG("Freeing duplicate ADS entries in link group table");
+       ret = link_groups_free_duplicate_data(lgt);
+       if (ret != 0)
+               goto out_free_lgt;
+       DEBUG("Done reading image metadata");
+
+       imd->lgt           = lgt;
+       imd->security_data = sd;
+       imd->root_dentry   = dentry;
+       goto out_free_buf;
+out_free_lgt:
+       free_link_group_table(lgt);
+out_free_dentry_tree:
        free_dentry_tree(dentry, NULL, false);
-err1:
+out_free_security_data:
+       free_security_data(sd);
+out_free_buf:
        FREE(buf);
        return ret;
 }
@@ -1016,7 +1039,7 @@ int write_metadata_resource(WIMStruct *w)
        u8 *buf;
        u8 *p;
        int ret;
-       off_t subdir_offset;
+       u64 subdir_offset;
        struct dentry *root;
        struct lookup_table_entry *lte;
        struct resource_entry *res_entry;
@@ -1026,7 +1049,7 @@ int write_metadata_resource(WIMStruct *w)
        int metadata_ctype;
        u8  hash[WIM_HASH_SIZE];
 
-       DEBUG("Writing metadata resource for image %u\n", w->current_image);
+       DEBUG("Writing metadata resource for image %d", w->current_image);
 
        out = w->out_fp;
        root = wim_root_dentry(w);
@@ -1035,30 +1058,23 @@ int write_metadata_resource(WIMStruct *w)
        if (metadata_offset == -1)
                return WIMLIB_ERR_WRITE;
 
-       #ifdef ENABLE_SECURITY_DATA
        struct wim_security_data *sd = wim_security_data(w);
        if (sd)
                subdir_offset = sd->total_length + root->length + 8;
        else
-       #endif
                subdir_offset = 8 + root->length + 8;
        calculate_subdir_offsets(root, &subdir_offset);
        metadata_original_size = subdir_offset;
        buf = MALLOC(metadata_original_size);
        if (!buf) {
                ERROR("Failed to allocate %"PRIu64" bytes for "
-                               "metadata resource\n", metadata_original_size);
+                     "metadata resource", metadata_original_size);
                return WIMLIB_ERR_NOMEM;
        }
-       #ifdef ENABLE_SECURITY_DATA
-       /* Write the security data. */
+
        p = write_security_data(sd, buf);
-       #else
-       p = put_u32(buf, 8); /* Total length of security data. */
-       p = put_u32(p, 0); /* Number of security data entries. */
-       #endif
 
-       DEBUG("Writing dentry tree.\n");
+       DEBUG("Writing dentry tree.");
        p = write_dentry_tree(root, p);
 
        /* Like file resources, the lookup table entry for a metadata resource
@@ -1075,6 +1091,9 @@ int write_metadata_resource(WIMStruct *w)
        if (ret != 0)
                return ret;
 
+       DEBUG("Updating metadata lookup table entry (size %zu)",
+             metadata_original_size);
+
        /* Update the lookup table entry, including the hash and output resource
         * entry fields, for this image's metadata resource.  */
        lte = wim_metadata_lookup_table_entry(w);
@@ -1094,73 +1113,74 @@ int write_metadata_resource(WIMStruct *w)
        return 0;
 }
 
-/* 
- * Writes a file resource to the output file. 
- *
- * @dentry:  The dentry for the file resource.
- * @wim_p:  A pointer to the WIMStruct.  The fields of interest to this
- *     function are the input and output file streams and the lookup table. 
- * @return zero on success, nonzero on failure. 
- */
-int write_file_resource(struct dentry *dentry, void *wim_p)
+static int write_file_resource(WIMStruct *w, const u8 hash[])
 {
-       WIMStruct *w;
-       FILE *out;
-       FILE *in;
-       struct lookup_table_entry *lte;
-       int in_wim_ctype;
-       int out_wim_ctype;
-       struct resource_entry *output_res_entry;
-       u64 len;
-       int ret;
-
-       w = wim_p;
-       out = w->out_fp;
-
-       /* Directories don't need file resources. */
-       if (dentry_is_directory(dentry))
-               return 0;
-
        /* Get the lookup entry for the file resource. */
-       lte = wim_lookup_resource(w, dentry);
+       struct lookup_table_entry *lte;
+       
+       lte = __lookup_resource(w->lookup_table, hash);
        if (!lte)
                return 0;
 
-       /* No need to write file resources twice.  (This indicates file
-        * resources that are part of a hard link set.) */
+       /* No need to write file resources twice. */
        if (++lte->out_refcnt != 1)
                return 0;
 
-       out_wim_ctype = wimlib_get_compression_type(w);
-       output_res_entry = &lte->output_resource_entry;
-
        /* do not write empty resources */
        if (lte->resource_entry.original_size == 0)
                return 0;
 
+       int out_wim_ctype = wimlib_get_compression_type(w);
+       struct resource_entry *output_res_entry = &lte->output_resource_entry;
+       u64 len;
+       FILE *in_fp;
+       FILE *out_fp = w->out_fp;
+       int ret = 0;
+
        /* Figure out if we can read the resource from the WIM file, or
-        * if we have to read it from the filesystem outside. */
-       if (lte->file_on_disk) {
+        * if we have to read it from the filesystem outside, or if it's a
+        * symbolic link with the data already in memory pointed to by a field
+        * of the lookup table entry. */
+       if (lte->is_symlink) {
+               off_t offset = ftello(w->out_fp);
+               u64 new_size;
+
+               if (offset == -1) {
+                       ERROR_WITH_ERRNO("Could not get position in output "
+                                        "file");
+                       return WIMLIB_ERR_WRITE;
+               }
+
+               wimlib_assert(lte->symlink_buf);
+
+               len = lte->resource_entry.original_size;
+
+               ret = recompress_resource(NULL, lte->symlink_buf, len, len, 0,
+                                         0, out_fp, out_wim_ctype, &new_size);
+               output_res_entry->size = new_size;
+               output_res_entry->original_size = len;
+               output_res_entry->offset = offset;
+               output_res_entry->flags = (out_wim_ctype == WIM_COMPRESSION_TYPE_NONE)
+                                               ? 0 : WIM_RESHDR_FLAG_COMPRESSED;
+       } else if (lte->file_on_disk) {
 
                /* Read from disk (uncompressed) */
 
                len = lte->resource_entry.original_size;
 
-               in = fopen(lte->file_on_disk, "rb");
-               if (!in) {
-                       ERROR("Failed to open the file `%s': %m\n",
-                                       lte->file_on_disk);
+               in_fp = fopen(lte->file_on_disk, "rb");
+               if (!in_fp) {
+                       ERROR_WITH_ERRNO("Failed to open the file `%s'",
+                                        lte->file_on_disk);
                        return WIMLIB_ERR_OPEN;
                }
 
-               if (w->verbose)
-                       puts(lte->file_on_disk);
-
-               ret = transfer_file_resource(in, len, len, 0,
-                                            WIM_COMPRESSION_TYPE_NONE, out, 
+               ret = transfer_file_resource(in_fp, len, len, 0,
+                                            WIM_COMPRESSION_TYPE_NONE, out_fp,
                                             out_wim_ctype, output_res_entry);
-               fclose(in);
+               fclose(in_fp);
        } else {
+               int in_wim_ctype;
 
                /* Read from input WIM (possibly compressed) */
 
@@ -1168,25 +1188,56 @@ int write_file_resource(struct dentry *dentry, void *wim_p)
                 * exporting images from one WIM file to another */
                if (lte->other_wim_fp) {
                        /* Different WIM file. */
-                       in = lte->other_wim_fp;
+                       in_fp = lte->other_wim_fp;
                        in_wim_ctype = lte->other_wim_ctype;
                } else {
                        /* Same WIM file. */
-                       in = w->fp;
+                       in_fp = w->fp;
                        in_wim_ctype = out_wim_ctype;
                }
                int input_res_ctype = resource_compression_type(
-                                       in_wim_ctype, 
-                                       lte->resource_entry.flags);
-
-               ret = transfer_file_resource(in
-                                       lte->resource_entry.size,
-                                       lte->resource_entry.original_size, 
-                                       lte->resource_entry.offset,
-                                       input_res_ctype, 
-                                       out, 
-                                       out_wim_ctype,
-                                       output_res_entry);
+                                               in_wim_ctype, 
+                                               lte->resource_entry.flags);
+
+               ret = transfer_file_resource(in_fp,
+                                            lte->resource_entry.size,
+                                            lte->resource_entry.original_size, 
+                                            lte->resource_entry.offset,
+                                            input_res_ctype, 
+                                            out_fp,
+                                            out_wim_ctype,
+                                            output_res_entry);
        }
        return ret;
 }
+
+/* 
+ * Writes a dentry's resources to the output file. 
+ *
+ * @dentry:  The dentry for the file resource.
+ * @wim_p:   A pointer to the WIMStruct.  The fields of interest to this
+ *          function are the input and output file streams and the lookup
+ *          table, and the alternate data streams.
+ *
+ * @return zero on success, nonzero on failure. 
+ */
+int write_dentry_resources(struct dentry *dentry, void *wim_p)
+{
+       WIMStruct *w = wim_p;
+       int ret;
+
+       /* Directories don't need file resources. */
+       if (dentry_is_directory(dentry))
+               return 0;
+
+       ret = write_file_resource(w, dentry->hash);
+       if (ret != 0)
+               return ret;
+       for (u16 i = 0; i < dentry->num_ads; i++) {
+               ret = write_file_resource(w, dentry->ads_entries[i].hash);
+               if (ret != 0)
+                       return ret;
+       }
+       return 0;
+}
+