*/
/*
- * Copyright (C) 2012-2016 Eric Biggers
+ * Copyright (C) 2012-2017 Eric Biggers
*
* 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
#include "wimlib/unix_data.h"
#include "wimlib/wim.h"
#include "wimlib/win32.h" /* for realpath() equivalent */
+#include "wimlib/xattr.h"
#include "wimlib/xml.h"
#define WIMLIB_EXTRACT_FLAG_FROM_PIPE 0x80000000
return end_file_phase(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_METADATA);
}
+/* Are all bytes in the specified buffer zero? */
+static bool
+is_all_zeroes(const u8 *p, const size_t size)
+{
+ const u8 * const end = p + size;
+
+ for (; (uintptr_t)p % WORDBYTES && p != end; p++)
+ if (*p)
+ return false;
+
+ for (; end - p >= WORDBYTES; p += WORDBYTES)
+ if (*(const machine_word_t *)p)
+ return false;
+
+ for (; p != end; p++)
+ if (*p)
+ return false;
+
+ return true;
+}
+
+/*
+ * Sparse regions should be detected at the granularity of the filesystem block
+ * size. For now just assume 4096 bytes, which is the default block size on
+ * NTFS and most Linux filesystems.
+ */
+#define SPARSE_UNIT 4096
+
+/*
+ * Detect whether the specified buffer begins with a region of all zero bytes.
+ * Return %true if a zero region was found or %false if a nonzero region was
+ * found, and sets *len_ret to the length of the region. This operates at a
+ * granularity of SPARSE_UNIT bytes, meaning that to extend a zero region, there
+ * must be SPARSE_UNIT zero bytes with no interruption, but to extend a nonzero
+ * region, just one nonzero byte in the next SPARSE_UNIT bytes is sufficient.
+ *
+ * Note: besides compression, the WIM format doesn't yet have a way to
+ * efficiently represent zero regions, so that's why we need to detect them
+ * ourselves. Things will still fall apart badly on extremely large sparse
+ * files, but this is a start...
+ */
+bool
+detect_sparse_region(const void *data, size_t size, size_t *len_ret)
+{
+ const void *p = data;
+ const void * const end = data + size;
+ size_t len = 0;
+ bool zeroes = false;
+
+ while (p != end) {
+ size_t n = min(end - p, SPARSE_UNIT);
+ bool z = is_all_zeroes(p, n);
+
+ if (len != 0 && z != zeroes)
+ break;
+ zeroes = z;
+ len += n;
+ p += n;
+ }
+
+ *len_ret = len;
+ return zeroes;
+}
+
#define PWM_FOUND_WIM_HDR (-1)
/* Read the header for a blob in a pipable WIM. If @pwm_hdr_ret is not NULL,
features->unix_data++;
if (inode_has_object_id(inode))
features->object_ids++;
+ if (inode_has_linux_xattrs(inode))
+ features->linux_xattrs++;
}
/* Tally features necessary to extract a dentry and the corresponding inode. */
WARNING("Ignoring Windows NT security descriptors of %lu files",
required_features->security_descriptors);
- /* UNIX data. */
- if ((extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) &&
- required_features->unix_data && !supported_features->unix_data)
+ /* Standard UNIX metadata */
+ if (required_features->unix_data &&
+ (!supported_features->unix_data ||
+ !(extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA)))
{
- ERROR("Extraction backend does not support UNIX data!");
- return WIMLIB_ERR_UNSUPPORTED;
+ if (extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
+ ERROR("Requested UNIX metadata extraction, but "
+ "extraction backend does not support it!");
+ return WIMLIB_ERR_UNSUPPORTED;
+ }
+ WARNING("Ignoring UNIX metadata (uid/gid/mode/rdev) of %lu files%"TS,
+ required_features->unix_data,
+ (supported_features->unix_data ?
+ T("\n (use --unix-data mode to extract these)") : T("")));
}
- if (required_features->unix_data &&
- !(extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA))
+ /* Linux-style extended attributes */
+ if (required_features->linux_xattrs &&
+ (!supported_features->linux_xattrs ||
+ !(extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA)))
{
- WARNING("Ignoring UNIX metadata of %lu files",
- required_features->unix_data);
+ WARNING("Ignoring Linux-style extended attributes of %lu files%"TS,
+ required_features->linux_xattrs,
+ (supported_features->linux_xattrs ?
+ T("\n (use --unix-data mode to extract these)") : T("")));
}
/* Object IDs. */