#include "wimlib/reparse.h"
#include "wimlib/wof.h"
-struct winnt_scan_stats {
+struct winnt_scan_ctx {
+ u32 vol_flags;
unsigned long num_get_sd_access_denied;
unsigned long num_get_sacl_priv_notheld;
+
+ /* True if WOF is definitely not attached to the volume being scanned;
+ * false if it may be */
+ bool wof_not_attached;
};
static inline const wchar_t *
static noinline_for_stack NTSTATUS
winnt_get_security_descriptor(HANDLE h, struct wim_inode *inode,
struct wim_sd_set *sd_set,
- struct winnt_scan_stats *stats, int add_flags)
+ struct winnt_scan_ctx *ctx, int add_flags)
{
SECURITY_INFORMATION requestedInformation;
u8 _buf[4096] _aligned_attribute(8);
}
if (requestedInformation & SACL_SECURITY_INFORMATION) {
/* Try again without the SACL. */
- stats->num_get_sacl_priv_notheld++;
+ ctx->num_get_sacl_priv_notheld++;
requestedInformation &= ~(SACL_SECURITY_INFORMATION |
LABEL_SECURITY_INFORMATION |
BACKUP_SECURITY_INFORMATION);
}
/* Fake success (useful when capturing as
* non-Administrator). */
- stats->num_get_sd_access_denied++;
+ ctx->num_get_sd_access_denied++;
status = STATUS_SUCCESS;
goto out_free_buf;
}
const wchar_t *filename,
size_t filename_nchars,
struct capture_params *params,
- struct winnt_scan_stats *stats,
- u32 vol_flags);
+ struct winnt_scan_ctx *ctx);
static int
winnt_recurse_directory(HANDLE h,
size_t full_path_nchars,
struct wim_dentry *parent,
struct capture_params *params,
- struct winnt_scan_stats *stats,
- u32 vol_flags)
+ struct winnt_scan_ctx *ctx)
{
void *buf;
const size_t bufsize = 8192;
filename,
info->FileNameLength / 2,
params,
- stats,
- vol_flags);
+ ctx);
full_path[full_path_nchars] = L'\0';
}
}
-/* Special case to better support in-place updates of backing WIM files: in
- * WIMBOOT mode, if the file is backed by a WIM (perhaps the WIM being updated)
- * and WOF is not attached to the volume, then capture the file as the
- * "dereferenced file" rather than as the "pointer file". Note that this only
- * requires stream manipulation --- there is no special handling of metadata
- * such as security descriptors required. */
+static inline bool
+should_try_to_use_wimboot_hash(const struct wim_inode *inode,
+ const struct winnt_scan_ctx *ctx,
+ const struct capture_params *params)
+{
+ /* Directories and encrypted files aren't valid for external backing. */
+ if (inode->i_attributes & (FILE_ATTRIBUTE_DIRECTORY |
+ FILE_ATTRIBUTE_ENCRYPTED))
+ return false;
+
+ /* If the file is a reparse point, then try the hash fixup if it's a WOF
+ * reparse point and we're in WIMBOOT mode. Otherwise, try the hash
+ * fixup if WOF may be attached. */
+ if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT)
+ return (inode->i_reparse_tag == WIM_IO_REPARSE_TAG_WOF) &&
+ (params->add_flags & WIMLIB_ADD_FLAG_WIMBOOT);
+ return !ctx->wof_not_attached;
+}
+
+/*
+ * This function implements an optimization for capturing files from a
+ * filesystem with a backing WIM(s). If a file is WIM-backed, then we can
+ * retrieve the SHA-1 message digest of its original contents from its reparse
+ * point. This may eliminate the need to read the file's data and/or allow the
+ * file's data to be immediately deduplicated with existing data in the WIM.
+ *
+ * If WOF is attached, then this function is merely an optimization, but
+ * potentially a very effective one. If WOF is detached, then this function
+ * really causes WIM-backed files to be, effectively, automatically
+ * "dereferenced" when possible; the unnamed data stream is updated to reference
+ * the original contents and the reparse point is removed.
+ *
+ * This function returns 0 if the fixup succeeded or was intentionally not
+ * executed. Otherwise it returns an error code.
+ */
static noinline_for_stack int
-fixup_wim_backed_file(struct wim_inode *inode, struct blob_table *blob_table)
+try_to_use_wimboot_hash(HANDLE h, struct wim_inode *inode,
+ struct blob_table *blob_table,
+ struct winnt_scan_ctx *ctx, const wchar_t *full_path)
{
+ struct wim_inode_stream *reparse_strm = NULL;
struct wim_inode_stream *strm;
struct blob_descriptor *blob;
- u8 _rpdata[REPARSE_DATA_MAX_SIZE] _aligned_attribute(8);
- struct {
- struct wof_external_info wof_info;
- struct wim_provider_rpdata wim_info;
- } *rpdata = (void *)_rpdata;
+ u8 hash[SHA1_HASH_SIZE];
int ret;
- strm = inode_get_unnamed_stream(inode, STREAM_TYPE_REPARSE_POINT);
- blob = stream_blob_resolved(strm);
- if (!blob || blob->size < sizeof(*rpdata))
- return 0;
+ if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
+ struct reparse_buffer_disk rpbuf;
+ struct {
+ struct wof_external_info wof_info;
+ struct wim_provider_rpdata wim_info;
+ } *rpdata = (void *)rpbuf.rpdata;
+ struct blob_descriptor *reparse_blob;
- ret = read_blob_into_buf(blob, rpdata);
- if (ret)
- return ret;
+ /* The file has a WOF reparse point, so WOF must be detached.
+ * We can read the reparse point directly. */
+ ctx->wof_not_attached = true;
+ reparse_strm = inode_get_unnamed_stream(inode, STREAM_TYPE_REPARSE_POINT);
+ reparse_blob = stream_blob_resolved(reparse_strm);
- if (rpdata->wof_info.version != WOF_CURRENT_VERSION ||
- rpdata->wof_info.provider != WOF_PROVIDER_WIM ||
- rpdata->wim_info.version != 2)
- return 0;
+ if (!reparse_blob || reparse_blob->size < sizeof(*rpdata))
+ return 0; /* Not a WIM-backed file */
- blob = lookup_blob(blob_table, rpdata->wim_info.unnamed_data_stream_hash);
- if (!blob)
- return 0;
+ ret = read_blob_into_buf(reparse_blob, rpdata);
+ if (ret)
+ return ret;
- /* All okay --- remove the reparse point and redirect the unnamed data
- * stream to the "dereferenced" one. */
- inode_remove_stream(inode, strm, blob_table);
+ if (rpdata->wof_info.version != WOF_CURRENT_VERSION ||
+ rpdata->wof_info.provider != WOF_PROVIDER_WIM ||
+ rpdata->wim_info.version != 2)
+ return 0; /* Not a WIM-backed file */
+
+ /* Okay, this is a WIM backed file. Get its SHA-1 hash. */
+ copy_hash(hash, rpdata->wim_info.unnamed_data_stream_hash);
+ } else {
+ struct {
+ struct wof_external_info wof_info;
+ struct wim_provider_external_info wim_info;
+ } out;
+ IO_STATUS_BLOCK iosb;
+ NTSTATUS status;
+
+ /* WOF may be attached. Try reading this file's external
+ * backing info. */
+ status = (*func_NtFsControlFile)(h, NULL, NULL, NULL, &iosb,
+ FSCTL_GET_EXTERNAL_BACKING,
+ NULL, 0, &out, sizeof(out));
+
+ /* Is WOF not attached? */
+ if (status == STATUS_INVALID_DEVICE_REQUEST) {
+ ctx->wof_not_attached = true;
+ return 0;
+ }
+
+ /* Is this file not externally backed? */
+ if (status == STATUS_OBJECT_NOT_EXTERNALLY_BACKED)
+ return 0;
+
+ /* Does this file have an unknown type of external backing that
+ * needed a larger information buffer? */
+ if (status == STATUS_BUFFER_TOO_SMALL)
+ return 0;
+
+ /* Was there some other failure? */
+ if (status != STATUS_SUCCESS) {
+ winnt_error(status,
+ L"\"%ls\": FSCTL_GET_EXTERNAL_BACKING failed",
+ full_path);
+ return WIMLIB_ERR_STAT;
+ }
+
+ /* Is this file backed by a WIM? */
+ if (out.wof_info.version != WOF_CURRENT_VERSION ||
+ out.wof_info.provider != WOF_PROVIDER_WIM ||
+ out.wim_info.version != WIM_PROVIDER_CURRENT_VERSION)
+ return 0;
+
+ /* Okay, this is a WIM backed file. Get its SHA-1 hash. */
+ copy_hash(hash, out.wim_info.unnamed_data_stream_hash);
+ }
+
+ /* If the file's unnamed data stream is nonempty, then fill in its hash
+ * and deduplicate it if possible.
+ *
+ * With WOF detached, we require that the blob *must* de-duplicable for
+ * any action can be taken, since without WOF we can't fall back to
+ * getting the "dereferenced" data by reading the stream (the real
+ * stream is sparse and contains all zeroes). */
strm = inode_get_unnamed_data_stream(inode);
- wimlib_assert(strm != NULL);
- inode_replace_stream_blob(inode, strm, blob, blob_table);
- inode->i_attributes &= ~(FILE_ATTRIBUTE_REPARSE_POINT |
- FILE_ATTRIBUTE_SPARSE_FILE);
- if (inode->i_attributes == 0)
- inode->i_attributes = FILE_ATTRIBUTE_NORMAL;
+ if (strm && (blob = stream_blob_resolved(strm))) {
+ struct blob_descriptor **back_ptr;
+
+ if (reparse_strm && !lookup_blob(blob_table, hash))
+ return 0;
+ back_ptr = retrieve_pointer_to_unhashed_blob(blob);
+ copy_hash(blob->hash, hash);
+ if (after_blob_hashed(blob, back_ptr, blob_table) != blob)
+ free_blob_descriptor(blob);
+ }
+
+ /* Remove the reparse point, if present. */
+ if (reparse_strm) {
+ inode_remove_stream(inode, reparse_strm, blob_table);
+ inode->i_attributes &= ~(FILE_ATTRIBUTE_REPARSE_POINT |
+ FILE_ATTRIBUTE_SPARSE_FILE);
+ if (inode->i_attributes == 0)
+ inode->i_attributes = FILE_ATTRIBUTE_NORMAL;
+ }
+
return 0;
}
const wchar_t *filename,
size_t filename_nchars,
struct capture_params *params,
- struct winnt_scan_stats *stats,
- u32 vol_flags)
+ struct winnt_scan_ctx *ctx)
{
struct wim_dentry *root = NULL;
struct wim_inode *inode = NULL;
if (unlikely(!cur_dir)) {
/* Root of tree being captured; get volume information. */
- vol_flags = get_volume_information(h, full_path, params);
+ ctx->vol_flags = get_volume_information(h, full_path, params);
params->capture_root_ino = file_info.ino;
}
/* Get the file's security descriptor, unless we are capturing in
* NO_ACLS mode or the volume does not support security descriptors. */
if (!(params->add_flags & WIMLIB_ADD_FLAG_NO_ACLS)
- && (vol_flags & FILE_PERSISTENT_ACLS))
+ && (ctx->vol_flags & FILE_PERSISTENT_ACLS))
{
status = winnt_get_security_descriptor(h, inode,
- params->sd_set, stats,
+ params->sd_set, ctx,
params->add_flags);
if (!NT_SUCCESS(status)) {
winnt_error(status,
inode,
params->unhashed_blobs,
file_info.end_of_file,
- vol_flags);
+ ctx->vol_flags);
if (ret)
goto out;
}
- if (unlikely((params->add_flags & WIMLIB_ADD_FLAG_WIMBOOT) &&
- (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) &&
- (inode->i_reparse_tag == WIM_IO_REPARSE_TAG_WOF)))
- {
- ret = fixup_wim_backed_file(inode, params->blob_table);
+ if (unlikely(should_try_to_use_wimboot_hash(inode, ctx, params))) {
+ ret = try_to_use_wimboot_hash(h, inode, params->blob_table, ctx,
+ full_path);
if (ret)
goto out;
}
full_path_nchars,
root,
params,
- stats,
- vol_flags);
+ ctx);
if (ret)
goto out;
}
}
static void
-winnt_do_scan_warnings(const wchar_t *path, const struct winnt_scan_stats *stats)
+winnt_do_scan_warnings(const wchar_t *path, const struct winnt_scan_ctx *ctx)
{
- if (likely(stats->num_get_sacl_priv_notheld == 0 &&
- stats->num_get_sd_access_denied == 0))
+ if (likely(ctx->num_get_sacl_priv_notheld == 0 &&
+ ctx->num_get_sd_access_denied == 0))
return;
WARNING("Scan of \"%ls\" complete, but with one or more warnings:", path);
- if (stats->num_get_sacl_priv_notheld != 0) {
+ if (ctx->num_get_sacl_priv_notheld != 0) {
WARNING("- Could not capture SACL (System Access Control List)\n"
" on %lu files or directories.",
- stats->num_get_sacl_priv_notheld);
+ ctx->num_get_sacl_priv_notheld);
}
- if (stats->num_get_sd_access_denied != 0) {
+ if (ctx->num_get_sd_access_denied != 0) {
WARNING("- Could not capture security descriptor at all\n"
" on %lu files or directories.",
- stats->num_get_sd_access_denied);
+ ctx->num_get_sd_access_denied);
}
WARNING("To fully capture all security descriptors, run the program\n"
" with Administrator rights.");
wchar_t *path;
int ret;
UNICODE_STRING ntpath;
- struct winnt_scan_stats stats;
+ struct winnt_scan_ctx ctx;
size_t ntpath_nchars;
/* WARNING: There is no check for overflow later when this buffer is
if (ret)
goto out_free_path;
- memset(&stats, 0, sizeof(stats));
+ memset(&ctx, 0, sizeof(ctx));
ret = winnt_build_dentry_tree_recursive(root_ret, NULL,
path, ntpath_nchars,
- L"", 0, params, &stats, 0);
+ L"", 0, params, &ctx);
out_free_path:
FREE(path);
if (ret == 0)
- winnt_do_scan_warnings(root_disk_path, &stats);
+ winnt_do_scan_warnings(root_disk_path, &ctx);
return ret;
}
git://wimlib.net / wimlib / blobdiff