s3 OneFS: Add shadow copy module

3 files changed, 1531 insertions, 0 deletions

diff --git a/source3/modules/onefs_shadow_copy.c b/source3/modules/onefs_shadow_copy.c
new file mode 100644
index 0000000000..5b02534715
--- /dev/null
+++ b/source3/modules/onefs_shadow_copy.c
@@ -0,0 +1,782 @@
+/*
+ * Unix SMB/CIFS implementation.
+ *
+ * OneFS shadow copy implementation that utilizes the file system's native
+ * snapshot support. This file does all of the heavy lifting.
+ *
+ * Copyright (C) Dave Richards, 2007
+ * Copyright (C) Tim Prouty, 2009
+ *
+ * This program 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.
+ *
+ * This program 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 details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <ifs/ifs_syscalls.h>
+#include <sys/types.h>
+#include <sys/isi_enc.h>
+#include <sys/module.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/time.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <search.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "onefs_shadow_copy.h"
+
+/* Copied from ../include/proto.h */
+void become_root(void);
+void unbecome_root(void);
+
+#define	SNAPSHOT_DIRECTORY	".snapshot"
+
+#define	MAX_VERSIONS		64
+
+/**
+ * A snapshot object.
+ *
+ * During snapshot enumeration, snapshots are represented by snapshot objects
+ * and are stored in a snapshot set.  The snapshot object represents one
+ * snapshot within the set.  An important thing to note about the set is that
+ * the key of the snapshot object is the tv_sec component of the is_time
+ * member.  What this means is that we only store one snapshot for each
+ * second.  If multiple snapshots were created within the same second, we'll
+ * keep the earliest one and ignore the rest.  Thus, not all snapshots are
+ * necessarily retained.
+ */
+struct osc_snapshot {
+	char *			is_name;
+	struct timespec		is_time;
+	struct osc_snapshot * 	is_next;
+};
+
+/**
+ * A snapshot context object.
+ *
+ * Snapshot contexts are used to pass information throughout the snapshot
+ * enumeration routines.  As a result, snapshot contexts are stored on the
+ * stack and are both created and destroyed within a single API function.
+ */
+struct osc_snapshot_ctx {
+	void *		osc_set;
+	struct timespec	osc_mtime;
+};
+
+/**
+ * A directory context.
+ *
+ * Directory contexts are the underlying data structured used to enumerate
+ * snapshot versions.  An opendir()-, readdir()- and closedir()-like interface
+ * is provided that utilizes directory contexts.  At the API level, directory
+ * contexts are passed around as void pointers.  Directory contexts are
+ * allocated on the heap and their lifetime is dictated by the calling
+ * routine.
+ */
+struct osc_directory_ctx {
+	size_t		idc_pos;
+	size_t		idc_len;
+	size_t		idc_size;
+	char **		idc_version;
+};
+
+/**
+ * Return a file descriptor to the STF names directory.
+ *
+ * Opens the STF names directory and returns a file descriptor to it.
+ * Subsequent calls return the same value (avoiding the need to re-open the
+ * directory repeatedly).  Caveat caller: don't close the file descriptor or
+ * you will be shot!
+ */
+static int
+osc_get_names_directory_fd(void)
+{
+	static int fd = -1;
+
+	if (fd == -1) {
+		become_root();
+		fd = pctl2_lin_open(STF_NAMES_LIN, HEAD_SNAPID, O_RDONLY);
+		unbecome_root();
+	}
+
+	return fd;
+}
+
+/**
+ * Compare two time values.
+ *
+ * Accepts two struct timespecs and compares the tv_sec components of these
+ * values.  It returns -1 if the first value preceeds the second, 0 if they
+ * are equal and +1 if the first values succeeds the second.
+ */
+static int
+osc_time_compare(const struct timespec *tsp1, const struct timespec *tsp2)
+{
+	return (tsp1->tv_sec < tsp2->tv_sec) ? -1 :
+	       (tsp1->tv_sec > tsp2->tv_sec) ? +1 : 0;
+}
+
+/**
+ * Compare two timespec values.
+ *
+ * Compares two timespec values.  It returns -1 if the first value preceeds
+ * the second, 0 if they are equal and +1 if the first values succeeds the
+ * second.
+ */
+static int
+osc_timespec_compare(const struct timespec *tsp1, const struct timespec *tsp2)
+{
+	return (tsp1->tv_sec  < tsp2->tv_sec)  ? -1 :
+	       (tsp1->tv_sec  > tsp2->tv_sec)  ? +1 :
+	       (tsp1->tv_nsec < tsp2->tv_nsec) ? -1 :
+	       (tsp1->tv_nsec > tsp2->tv_nsec) ? +1 : 0;
+}
+
+/**
+ * Determine whether a timespec value is zero.
+ *
+ * Return 1 if the struct timespec provided is zero and 0 otherwise.
+ */
+static int
+osc_timespec_is_zero(const struct timespec *tsp)
+{
+	return (tsp->tv_sec  == 0) &&
+	       (tsp->tv_nsec == 0);
+}
+
+/**
+ * Create a snapshot object.
+ *
+ * Allocates and initializes a new snapshot object.  In addition to allocating
+ * space for the snapshot object itself, space is allocated for the snapshot
+ * name.  Both the name and time are then copied to the new object.
+ */
+static struct osc_snapshot *
+osc_snapshot_create(const char *name, const struct timespec *tsp)
+{
+	struct osc_snapshot *isp;
+
+	isp = malloc(sizeof *isp);
+	if (isp == NULL)
+		goto out;
+
+	isp->is_name = malloc(strlen(name) + 1);
+	if (isp->is_name == NULL) {
+		free(isp);
+		isp = NULL;
+		goto out;
+	}
+
+	strcpy(isp->is_name, name);
+	isp->is_time = *tsp;
+	isp->is_next = NULL;
+
+ out:
+	return isp;
+}
+
+/**
+ * Destroy a snapshot object.
+ *
+ * Frees both the name and the snapshot object itself.  Appropriate NULL
+ * checking is performed because counting on free to do so is immoral.
+ */
+static void
+osc_snapshot_destroy(struct osc_snapshot *isp)
+{
+	if (isp != NULL) {
+		if (isp->is_name != NULL)
+			free(isp->is_name);
+		free(isp);
+	}
+}
+
+/**
+ * Destroy all snapshots in the snapshot list.
+ *
+ * Calls osc_snapshot_destroy() on each snapshot in the list.
+ */
+static void
+osc_snapshot_destroy_list(struct osc_snapshot *isp)
+{
+	struct osc_snapshot *tmp;
+
+	while (isp != NULL) {
+		tmp = isp;
+		isp = isp->is_next;
+		osc_snapshot_destroy(tmp);
+	}
+}
+
+/**
+ * Compare two snapshot objects.
+ *
+ * Compare two snapshot objects.  It is really just a wrapper for
+ * osc_time_compare(), which compare the time value of the two snapshots.
+ * N.B. time value in this context refers only to the tv_sec component.
+ */
+static int
+osc_snapshot_compare(const void *vp1, const void *vp2)
+{
+	const struct osc_snapshot *isp1 = vp1;
+	const struct osc_snapshot *isp2 = vp2;
+
+	return -osc_time_compare(&isp1->is_time, &isp2->is_time);
+}
+
+/**
+ * Insert a snapshot into the snapshot set.
+ *
+ * Inserts a new snapshot into the snapshot set.  The key for snapshots is
+ * their creation time (it's actually the seconds portion of the creation
+ * time).  If a duplicate snapshot is found in the set, the new snapshot is
+ * added to a linked list of snapshots for that second.
+ */
+static void
+osc_snapshot_insert(struct osc_snapshot_ctx *oscp, const char *name,
+    const struct timespec *tsp, int *errorp)
+{
+	struct osc_snapshot *isp1;
+	struct osc_snapshot **ispp;
+
+	isp1 = osc_snapshot_create(name, tsp);
+	if (isp1 == NULL) {
+		*errorp = 1;
+		return;
+	}
+
+	ispp = tsearch(isp1, &oscp->osc_set, osc_snapshot_compare);
+	if (ispp != NULL) {
+		struct osc_snapshot *isp2 = *ispp;
+
+		/* If this is the only snapshot for this second, we're done. */
+		if (isp2 == isp1)
+			return;
+
+		/* Collision: add the new snapshot to the list. */
+		isp1->is_next = isp2->is_next;
+		isp2->is_next = isp1;
+
+	} else
+		*errorp = 1;
+
+}
+
+/**
+ * Process the next snapshot.
+ *
+ * Called for (almost) every entry in a .snapshot directory, ("." and ".." are
+ * ignored in osc_process_snapshot_directory()).  All other entries are passed
+ * to osc_process_snapshot(), however.  These entries can fall into one of two
+ * categories: snapshot names and snapshot aliases.  We only care about
+ * snapshot names (as aliases are just redundant entries).  Once it verifies
+ * that name represents a valid snapshot name, it calls fstat() to get the
+ * creation time of the snapshot and then calls osc_snapshot_insert() to add
+ * this entry to the snapshot set.
+ */
+static void
+osc_process_snapshot(struct osc_snapshot_ctx *oscp, const char *name,
+    int *errorp)
+{
+	int fd;
+	struct stf_stat stf_stat;
+	struct stat stbuf;
+
+	fd = osc_get_names_directory_fd();
+	if (fd == -1)
+		goto out;
+
+	fd = enc_openat(fd, name, ENC_DEFAULT, O_RDONLY);
+	if (fd == -1)
+		goto out;
+
+	memset(&stf_stat, 0, sizeof stf_stat);
+	if (ifs_snap_stat(fd, &stf_stat) == -1)
+		goto out;
+
+	if (stf_stat.sf_type != SF_STF)
+		goto out;
+
+	if (fstat(fd, &stbuf) == -1)
+		goto out;
+
+	osc_snapshot_insert(oscp, name, &stbuf.st_birthtimespec, errorp);
+
+ out:
+	if (fd != -1)
+		close(fd);
+}
+
+/**
+ * Process a snapshot directory.
+ *
+ * Opens the snapshot directory and calls osc_process_snapshot() for each
+ * entry.  (Well ok, "." and ".."  are ignored.)  The goal here is to add all
+ * snapshots in the directory to the snapshot set.
+ */
+static void
+osc_process_snapshot_directory(struct osc_snapshot_ctx *oscp, int *errorp)
+{
+	int fd;
+	struct stat stbuf;
+	DIR *dirp;
+	struct dirent *dp;
+
+	fd = osc_get_names_directory_fd();
+	if (fd == -1)
+		goto out;
+
+	if (fstat(fd, &stbuf) == -1)
+		goto out;
+
+	dirp = opendir(SNAPSHOT_DIRECTORY);
+	if (dirp == NULL)
+		goto out;
+
+	for (;;) {
+		dp = readdir(dirp);
+		if (dp == NULL)
+			break;
+
+		if (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' ||
+		    (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
+			continue;
+
+		osc_process_snapshot(oscp, dp->d_name, errorp);
+		if (*errorp)
+			break;
+	}
+
+	closedir(dirp);
+
+	if (!*errorp)
+		oscp->osc_mtime = stbuf.st_mtimespec;
+
+ out:
+	return;
+}
+
+/**
+ * Initialize a snapshot context object.
+ *
+ * Clears all members of the context object.
+ */
+static void
+osc_snapshot_ctx_init(struct osc_snapshot_ctx *oscp)
+{
+	memset(oscp, 0, sizeof *oscp);
+}
+
+/**
+ * Desoy a snapshot context object.
+ *
+ * Frees all snapshots associated with the snapshot context and then calls
+ * osc_snapshot_ctx_init() to re-initialize the context object.
+ */
+static void
+osc_snapshot_ctx_clean(struct osc_snapshot_ctx *oscp)
+{
+	struct osc_snapshot *tmp;
+
+	while (oscp->osc_set != NULL) {
+		tmp = *(void **)oscp->osc_set;
+		tdelete(tmp, &oscp->osc_set, osc_snapshot_compare);
+		osc_snapshot_destroy_list(tmp);
+	}
+
+	osc_snapshot_ctx_init(oscp);
+}
+
+/**
+ * Return the "global" snapshot context.
+ *
+ * We maintain a single open snapshot context.  Return a pointer to it.
+ */
+static struct osc_snapshot_ctx *
+osc_get_snapshot_ctx(void)
+{
+	static struct osc_snapshot_ctx osc = { 0, { 0, 0 } };
+
+	return &osc;
+}
+
+/**
+ * Determine whether a snapshot context is still valid.
+ *
+ * "Valid" in this context means "reusable".  We can re-use a previous
+ * snapshot context iff we successfully built a previous snapshot context
+ * and no snapshots have been created or deleted since we did so.
+ * A "names" directory exists within our snapshot
+ * implementation in which all snapshot names are entered.  Each time a
+ * snapshot is created or deleted, an entry must be added or removed.
+ * When this happens the modification time on the "names" directory
+ * changes.  Therefore, a snapshot context is valid iff the context
+ * pointer is non-NULL, the cached modification time is non-zero
+ * (zero means uninitialized), and the modification time of the "names"
+ * directory matches the cached value.
+ */
+static int
+osc_snapshot_ctx_is_valid(struct osc_snapshot_ctx *oscp)
+{
+	int fd;
+	struct stat stbuf;
+
+	if (oscp == NULL)
+		return 0;
+
+	if (osc_timespec_is_zero(&oscp->osc_mtime))
+		return 0;
+
+	fd = osc_get_names_directory_fd();
+	if (fd == -1)
+		return 0;
+
+	if (fstat(fd, &stbuf) == -1)
+		return 0;
+
+	if (osc_timespec_compare(&oscp->osc_mtime, &stbuf.st_mtimespec) != 0)
+		return 0;
+
+	return 1;
+}
+
+/**
+ * Create and initialize a directory context.
+ *
+ * Allocates a directory context from the heap and initializes it.
+ */
+static struct osc_directory_ctx *
+osc_directory_ctx_create(void)
+{
+	struct osc_directory_ctx *idcp;
+
+	idcp = malloc(sizeof *idcp);
+	if (idcp != NULL)
+		memset(idcp, 0, sizeof *idcp);
+
+	return idcp;
+}
+
+/**
+ * Destroy a directory context.
+ *
+ * Frees any versions associated with the directory context and then frees the
+ * context itself.
+ */
+static void
+osc_directory_ctx_destroy(struct osc_directory_ctx *idcp)
+{
+	int i;
+
+	if (idcp == NULL)
+		return;
+
+	for (i = 0; i < idcp->idc_len; i++)
+		free(idcp->idc_version[i]);
+
+	free(idcp);
+}
+
+/**
+ * Expand the size of a directory context's version list.
+ *
+ * If osc_directory_ctx_append_version() detects that the version list is too
+ * small to accomodate a new version string, it called
+ * osc_directory_ctx_expand_version_list() to expand the version list.
+ */
+static void
+osc_directory_ctx_expand_version_list(struct osc_snapshot_ctx *oscp,
+    struct osc_directory_ctx *idcp, int *errorp)
+{
+	size_t size;
+	char **cpp;
+
+	size = idcp->idc_size * 2 ?: 1;
+
+	cpp = realloc(idcp->idc_version, size * sizeof (char *));
+	if (cpp == NULL) {
+		*errorp = 1;
+		return;
+	}
+
+	idcp->idc_size = size;
+	idcp->idc_version = cpp;
+}
+
+/**
+ * Append a new version to a directory context.
+ *
+ * Appends a snapshot version to the
+ * directory context's version list.
+ */
+static void
+osc_directory_ctx_append_version(struct osc_snapshot_ctx *oscp,
+    struct osc_directory_ctx *idcp, const struct timespec *tsp, int *errorp)
+{
+	char *cp;
+	struct tm *tmp;
+	char text[64];
+
+	if (idcp->idc_len >= MAX_VERSIONS)
+		return;
+
+	if (idcp->idc_len >= idcp->idc_size) {
+		osc_directory_ctx_expand_version_list(oscp, idcp, errorp);
+		if (*errorp)
+			return;
+	}
+
+	tmp = gmtime(&tsp->tv_sec);
+	if (tmp == NULL) {
+		*errorp = 1;
+		return;
+	}
+
+	snprintf(text, sizeof text,
+	    "@GMT-%04u.%02u.%02u-%02u.%02u.%02u",
+	    tmp->tm_year + 1900,
+	    tmp->tm_mon + 1,
+	    tmp->tm_mday,
+	    tmp->tm_hour,
+	    tmp->tm_min,
+	    tmp->tm_sec);
+
+	cp = malloc(strlen(text) + 1);
+	if (cp == NULL) {
+		*errorp = 1;
+		return;
+	}
+
+	strcpy(cp, text);
+
+	idcp->idc_version[idcp->idc_len++] = cp;
+}
+
+/**
+ * Make a directory context from a snapshot context.
+ *
+ * Once a snapshot context has been completely filled-in,
+ * osc_make_directory_ctx() is used to build a directory context from it.  The
+ * idea here is to create version for each snapshot in the snapshot set.
+ */
+static void
+osc_make_directory_ctx(struct osc_snapshot_ctx *oscp,
+    struct osc_directory_ctx *idcp, int *errorp)
+{
+	static void
+	walk(const void *vp, VISIT v, int level)
+	{
+		const struct osc_snapshot *isp;
+
+		if ((v != postorder && v != leaf) || *errorp)
+			return;
+
+		isp = *(const struct osc_snapshot **)(u_long)vp;
+
+		osc_directory_ctx_append_version(oscp, idcp, &isp->is_time,
+		    errorp);
+	}
+
+	twalk(oscp->osc_set, walk);
+}
+
+/**
+ * Open a version directory.
+ *
+ * Opens a version directory.  What this really means is that
+ * osc_version_opendir() returns a handle to a directory context, which can be
+ * used to retrieve version strings.
+ */
+void *
+osc_version_opendir(void)
+{
+	int error = 0;
+	struct osc_directory_ctx *idcp;
+	struct osc_snapshot_ctx *oscp;
+
+	idcp = osc_directory_ctx_create();
+	if (idcp == NULL)
+		goto error_out;
+
+	oscp = osc_get_snapshot_ctx();
+
+	if (!osc_snapshot_ctx_is_valid(oscp)) {
+		osc_snapshot_ctx_clean(oscp);
+		osc_process_snapshot_directory(oscp, &error);
+		if (error)
+			goto error_out;
+	}
+
+	osc_make_directory_ctx(oscp, idcp, &error);
+	if (error)
+		goto error_out;
+
+	goto out;
+
+ error_out:
+	if (idcp != NULL) {
+		osc_directory_ctx_destroy(idcp);
+		idcp = NULL;
+	}
+
+ out:
+	return (void *)idcp;
+}
+
+/**
+ * Read the next version directory entry.
+ *
+ * Returns the name of the next version in the version directory, or NULL if
+ * we're at the end of the directory.  What this really does is return the
+ * next version from the version list stored in the directory context.
+ */
+char *
+osc_version_readdir(void *vp)
+{
+	struct osc_directory_ctx *idcp = vp;
+
+	if (idcp == NULL)
+		return NULL;
+
+	if (idcp->idc_pos >= idcp->idc_len)
+		return NULL;
+
+	return idcp->idc_version[idcp->idc_pos++];
+}
+
+/**
+ * Close the version directory.
+ *
+ * Destroys the underlying directory context.
+ */
+void
+osc_version_closedir(void *vp)
+{
+	struct osc_directory_ctx *idcp = vp;
+
+	if (idcp != NULL)
+		osc_directory_ctx_destroy(idcp);
+}
+
+/**
+ * Canonicalize a path.
+ *
+ * Converts paths of the form @GMT-.. to paths of the form ../.snapshot/..
+ * It's not the prettiest routine I've ever written, but what the heck?
+ */
+char *
+osc_canonicalize_path(const char *path, char *snap_component)
+{
+	int error = 0;
+	struct osc_snapshot_ctx *oscp;
+	struct tm tm;
+	int n;
+	struct osc_snapshot is;
+	struct osc_snapshot **ispp;
+	struct osc_snapshot *isp;
+	char *cpath = NULL;
+	char *cpath2 = NULL;
+	const char *snap_component_orig = snap_component;
+	struct stat sb;
+
+	oscp = osc_get_snapshot_ctx();
+
+	if (!osc_snapshot_ctx_is_valid(oscp)) {
+		osc_snapshot_ctx_clean(oscp);
+		osc_process_snapshot_directory(oscp, &error);
+		if (error)
+			goto out;
+	}
+
+	memset(&tm, 0, sizeof tm);
+	n = sscanf(snap_component,
+	    "@GMT-%4u.%2u.%2u-%2u.%2u.%2u",
+	    &tm.tm_year,
+	    &tm.tm_mon,
+	    &tm.tm_mday,
+	    &tm.tm_hour,
+	    &tm.tm_min,
+	    &tm.tm_sec);
+	if (n != 6)
+		goto out;
+
+	tm.tm_year -= 1900;
+	tm.tm_mon -= 1;
+
+	is.is_name = NULL;
+	is.is_time.tv_sec = timegm(&tm);
+	is.is_time.tv_nsec = 0;
+
+	ispp = tfind(&is, &oscp->osc_set, osc_snapshot_compare);
+	if (ispp == NULL)
+		goto out;
+	isp = *ispp;
+
+	/* Determine the path after "@GMT-..." */
+	while (*snap_component != '/' && *snap_component != '\0')
+		snap_component++;
+
+	while (*snap_component == '/')
+		snap_component++;
+
+	cpath = malloc(strlen(SNAPSHOT_DIRECTORY) + strlen(isp->is_name) +
+	    strlen(path) + 3);
+
+	if (cpath == NULL)
+		goto out;
+
+	/*
+	 * Use the first snapshot that has a successful stat for the requested
+	 * path.
+	 */
+	while (true) {
+
+		sprintf(cpath, "%s/%s", SNAPSHOT_DIRECTORY, isp->is_name);
+
+		/* Append path before "@GMT-..." */
+		if (snap_component_orig != path) {
+			strcat(cpath, "/");
+			strncat(cpath, path, snap_component_orig - path);
+		}
+
+		/* Append path after "@GMT-..." */
+		if (*snap_component != '\0') {
+			strcat(cpath, "/");
+			strcat(cpath, snap_component);
+		}
+
+		/* If there is a valid snapshot for this file, we're done. */
+		if (stat(cpath, &sb) == 0)
+			break;
+
+		/* Try the next snapshot. If this was the last one, give up. */
+		isp = isp->is_next;
+		if (isp == NULL)
+			break;
+
+		/* If the realloc fails, give up. */
+		cpath2 = realloc(cpath, strlen(SNAPSHOT_DIRECTORY) +
+		    strlen(isp->is_name) + strlen(path) + 3);
+		if (cpath2 == NULL)
+			break;
+		cpath = cpath2;
+	}
+
+ out:
+	return cpath;
+}
diff --git a/source3/modules/onefs_shadow_copy.h b/source3/modules/onefs_shadow_copy.h
new file mode 100644
index 0000000000..6415a4be1a
--- /dev/null
+++ b/source3/modules/onefs_shadow_copy.h
@@ -0,0 +1,32 @@
+/*
+ * Unix SMB/CIFS implementation.
+ *
+ * OneFS shadow copy implementation that utilizes the file system's native
+ * snapshot support.
+ *
+ * Copyright (C) Dave Richards, 2007
+ * Copyright (C) Tim Prouty, 2009
+ *
+ * This program 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.
+ *
+ * This program 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 details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef ONEFS_SHADOW_COPY_H
+#define	 ONEFS_SHADOW_COPY_H
+
+void *osc_version_opendir(void);
+char *osc_version_readdir(void *vp);
+void osc_version_closedir(void *vp);
+char *osc_canonicalize_path(const char *path, char *snap_component);
+
+#endif /* ONEFS_SHADOW_COPY_H */
diff --git a/source3/modules/vfs_onefs_shadow_copy.c b/source3/modules/vfs_onefs_shadow_copy.c
new file mode 100644
index 0000000000..28bc0c5081
--- /dev/null
+++ b/source3/modules/vfs_onefs_shadow_copy.c
@@ -0,0 +1,717 @@
+/*
+ * OneFS shadow copy implementation that utilizes the file system's native
+ * snapshot support. This is based on the original shadow copy module from
+ * 2004.
+ *
+ * Copyright (C) Stefan Metzmacher	2003-2004
+ * Copyright (C) Tim Prouty		2009
+ *
+ * This program 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "includes.h"
+#include "onefs_shadow_copy.h"
+
+static int vfs_onefs_shadow_copy_debug_level = DBGC_VFS;
+
+#undef DBGC_CLASS
+#define DBGC_CLASS vfs_onefs_shadow_copy_debug_level
+
+#define SHADOW_COPY_PREFIX "@GMT-"
+#define SHADOW_COPY_SAMPLE "@GMT-2004.02.18-15.44.00"
+
+bool
+shadow_copy_match_name(const char *name, char **snap_component)
+{
+	uint32  i = 0;
+	char delim[] = SHADOW_COPY_PREFIX;
+	char* start;
+
+	start = strstr( name, delim );
+
+	/*
+	 * The name could have SHADOW_COPY_PREFIX in it so we need to keep
+	 * trying until we get something that is the full length of the
+	 * SHADOW_COPY_SAMPLE.
+	 */
+	while (start != NULL) {
+
+		DEBUG(10,("Processing %s\n", name));
+
+		/* size / correctness check */
+		*snap_component = start;
+		for ( i = sizeof(SHADOW_COPY_PREFIX);
+		      i < sizeof(SHADOW_COPY_SAMPLE); i++) {
+			if (start[i] == '/') {
+				if (i == sizeof(SHADOW_COPY_SAMPLE) - 1)
+					return true;
+				else
+					break;
+			} else if (start[i] == '\0')
+				return (i == sizeof(SHADOW_COPY_SAMPLE) - 1);
+		}
+
+		start = strstr( start, delim );
+	}
+
+	return false;
+}
+
+static int
+onefs_shadow_copy_get_shadow_copy_data(vfs_handle_struct *handle,
+				       files_struct *fsp,
+				       SHADOW_COPY_DATA *shadow_copy_data,
+				       bool labels)
+{
+	void *p = osc_version_opendir();
+	char *snap_component = NULL;
+	shadow_copy_data->num_volumes = 0;
+	shadow_copy_data->labels = NULL;
+
+	if (!p) {
+		DEBUG(0, ("shadow_copy_get_shadow_copy_data: osc_opendir() "
+			  "failed for [%s]\n",fsp->conn->connectpath));
+		return -1;
+	}
+
+	while (true) {
+		SHADOW_COPY_LABEL *tlabels;
+		char *d;
+
+		d = osc_version_readdir(p);
+		if (d == NULL)
+			break;
+
+		if (!shadow_copy_match_name(d, &snap_component)) {
+			DEBUG(10,("shadow_copy_get_shadow_copy_data: ignore "
+				  "[%s]\n",d));
+			continue;
+		}
+
+		DEBUG(7,("shadow_copy_get_shadow_copy_data: not ignore "
+			 "[%s]\n",d));
+
+		if (!labels) {
+			shadow_copy_data->num_volumes++;
+			continue;
+		}
+
+		tlabels = (SHADOW_COPY_LABEL *)TALLOC_REALLOC(
+			shadow_copy_data->mem_ctx,
+			shadow_copy_data->labels,
+			(shadow_copy_data->num_volumes+1) *
+			sizeof(SHADOW_COPY_LABEL));
+
+		if (tlabels == NULL) {
+			DEBUG(0,("shadow_copy_get_shadow_copy_data: Out of "
+				 "memory\n"));
+			osc_version_closedir(p);
+			return -1;
+		}
+
+		snprintf(tlabels[shadow_copy_data->num_volumes++],
+			 sizeof(*tlabels), "%s",d);
+
+		shadow_copy_data->labels = tlabels;
+	}
+
+	osc_version_closedir(p);
+
+	return 0;
+}
+
+#define SHADOW_NEXT(op, args, rtype) do {			      \
+	char *cpath = NULL;					      \
+	char *snap_component = NULL;				      \
+	rtype ret;						      \
+	if (shadow_copy_match_name(path, &snap_component))	      \
+		cpath = osc_canonicalize_path(path, snap_component); \
+	ret = SMB_VFS_NEXT_ ## op args;				      \
+	SAFE_FREE(cpath);					      \
+	return ret;						      \
+	} while (0)						      \
+
+
+
+static uint64_t
+onefs_shadow_copy_disk_free(vfs_handle_struct *handle, const char *path,
+			    bool small_query, uint64_t *bsize, uint64_t *dfree,
+			    uint64_t *dsize)
+{
+
+	SHADOW_NEXT(DISK_FREE,
+		    (handle, cpath ?: path, small_query, bsize, dfree, dsize),
+		    uint64_t);
+
+}
+
+static int
+onefs_shadow_copy_statvfs(struct vfs_handle_struct *handle, const char *path,
+			  struct vfs_statvfs_struct *statbuf)
+{
+	SHADOW_NEXT(STATVFS,
+		    (handle, cpath ?: path, statbuf),
+		    int);
+}
+
+static SMB_STRUCT_DIR *
+onefs_shadow_copy_opendir(vfs_handle_struct *handle, const char *path,
+			  const char *mask, uint32_t attr)
+{
+	SHADOW_NEXT(OPENDIR,
+		    (handle, cpath ?: path, mask, attr),
+		    SMB_STRUCT_DIR *);
+}
+
+static int
+onefs_shadow_copy_mkdir(vfs_handle_struct *handle, const char *path,
+			mode_t mode)
+{
+	SHADOW_NEXT(MKDIR,
+		    (handle, cpath ?: path, mode),
+		    int);
+}
+
+static int
+onefs_shadow_copy_rmdir(vfs_handle_struct *handle, const char *path)
+{
+	SHADOW_NEXT(RMDIR,
+		    (handle, cpath ?: path),
+		    int);
+}
+
+static int
+onefs_shadow_copy_open(vfs_handle_struct *handle, const char *path,
+		       files_struct *fsp, int flags, mode_t mode)
+{
+	SHADOW_NEXT(OPEN,
+		    (handle, cpath ?: path, fsp, flags, mode),
+		    int);
+}
+
+static NTSTATUS
+onefs_shadow_copy_create_file(vfs_handle_struct *handle,
+			      struct smb_request *req,
+			      uint16_t root_dir_fid,
+			      const char *path,
+			      uint32_t create_file_flags,
+			      uint32_t access_mask,
+			      uint32_t share_access,
+			      uint32_t create_disposition,
+			      uint32_t create_options,
+			      uint32_t file_attributes,
+			      uint32_t oplock_request,
+			      uint64_t allocation_size,
+			      struct security_descriptor *sd,
+			      struct ea_list *ea_list,
+			      files_struct **result,
+			      int *pinfo,
+			      SMB_STRUCT_STAT *psbuf)
+{
+	SHADOW_NEXT(CREATE_FILE,
+		    (handle, req, root_dir_fid, cpath ?: path,
+			create_file_flags, access_mask, share_access,
+			create_disposition, create_options, file_attributes,
+			oplock_request, allocation_size, sd, ea_list, result,
+			pinfo, psbuf),
+		    NTSTATUS);
+}
+
+/**
+ * XXX: macro-ize
+ */
+static int
+onefs_shadow_copy_rename(vfs_handle_struct *handle, const char *old_name,
+			 const char *new_name)
+{
+	char *old_cpath = NULL;
+	char *old_snap_component = NULL;
+	char *new_cpath = NULL;
+	char *new_snap_component = NULL;
+	int ret;
+
+	if (shadow_copy_match_name(old_name, &old_snap_component))
+		old_cpath = osc_canonicalize_path(old_name, old_snap_component);
+
+	if (shadow_copy_match_name(new_name, &new_snap_component))
+		new_cpath = osc_canonicalize_path(new_name, new_snap_component);
+
+        ret = SMB_VFS_NEXT_RENAME(handle, old_cpath ?: old_name,
+	    new_cpath ?: new_name);
+
+	SAFE_FREE(old_cpath);
+	SAFE_FREE(new_cpath);
+
+	return ret;
+}
+
+static int
+onefs_shadow_copy_stat(vfs_handle_struct *handle, const char *path,
+		       SMB_STRUCT_STAT *sbuf)
+{
+	SHADOW_NEXT(STAT,
+		    (handle, cpath ?: path, sbuf),
+		    int);
+}
+
+static int
+onefs_shadow_copy_lstat(vfs_handle_struct *handle, const char *path,
+			SMB_STRUCT_STAT *sbuf)
+{
+	SHADOW_NEXT(LSTAT,
+		    (handle, cpath ?: path, sbuf),
+		    int);
+}
+
+static int
+onefs_shadow_copy_unlink(vfs_handle_struct *handle, const char *path)
+{
+	SHADOW_NEXT(UNLINK,
+		    (handle, cpath ?: path),
+		    int);
+}
+
+static int
+onefs_shadow_copy_chmod(vfs_handle_struct *handle, const char *path,
+			mode_t mode)
+{
+	SHADOW_NEXT(CHMOD,
+		    (handle, cpath ?: path, mode),
+		    int);
+}
+
+static int
+onefs_shadow_copy_chown(vfs_handle_struct *handle, const char *path,
+			uid_t uid, gid_t gid)
+{
+	SHADOW_NEXT(CHOWN,
+		    (handle, cpath ?: path, uid, gid),
+		    int);
+}
+
+static int
+onefs_shadow_copy_lchown(vfs_handle_struct *handle, const char *path,
+			 uid_t uid, gid_t gid)
+{
+	SHADOW_NEXT(LCHOWN,
+		    (handle, cpath ?: path, uid, gid),
+		    int);
+}
+
+static int
+onefs_shadow_copy_chdir(vfs_handle_struct *handle, const char *path)
+{
+	SHADOW_NEXT(CHDIR,
+		    (handle, cpath ?: path),
+		    int);
+}
+
+static int
+onefs_shadow_copy_ntimes(vfs_handle_struct *handle, const char *path,
+			struct smb_file_time *ft)
+{
+	SHADOW_NEXT(NTIMES,
+		    (handle, cpath ?: path, ft),
+		    int);
+
+}
+
+/**
+ * XXX: macro-ize
+ */
+static bool
+onefs_shadow_copy_symlink(vfs_handle_struct *handle,
+    const char *oldpath, const char *newpath)
+{
+	char *old_cpath = NULL;
+	char *old_snap_component = NULL;
+	char *new_cpath = NULL;
+	char *new_snap_component = NULL;
+	bool ret;
+
+	if (shadow_copy_match_name(oldpath, &old_snap_component))
+		old_cpath = osc_canonicalize_path(oldpath, old_snap_component);
+
+	if (shadow_copy_match_name(newpath, &new_snap_component))
+		new_cpath = osc_canonicalize_path(newpath, new_snap_component);
+
+        ret = SMB_VFS_NEXT_SYMLINK(handle, old_cpath ?: oldpath,
+	    new_cpath ?: newpath);
+
+	SAFE_FREE(old_cpath);
+	SAFE_FREE(new_cpath);
+
+	return ret;
+}
+
+static bool
+onefs_shadow_copy_readlink(vfs_handle_struct *handle, const char *path,
+			   char *buf, size_t bufsiz)
+{
+	SHADOW_NEXT(READLINK,
+		    (handle, cpath ?: path, buf, bufsiz),
+		    bool);
+}
+
+/**
+ * XXX: macro-ize
+ */
+static int
+onefs_shadow_copy_link(vfs_handle_struct *handle, const char *oldpath,
+		       const char *newpath)
+{
+	char *old_cpath = NULL;
+	char *old_snap_component = NULL;
+	char *new_cpath = NULL;
+	char *new_snap_component = NULL;
+	int ret;
+
+	if (shadow_copy_match_name(oldpath, &old_snap_component))
+		old_cpath = osc_canonicalize_path(oldpath, old_snap_component);
+
+	if (shadow_copy_match_name(newpath, &new_snap_component))
+		new_cpath = osc_canonicalize_path(newpath, new_snap_component);
+
+        ret = SMB_VFS_NEXT_LINK(handle, old_cpath ?: oldpath,
+	    new_cpath ?: newpath);
+
+	SAFE_FREE(old_cpath);
+	SAFE_FREE(new_cpath);
+
+	return ret;
+}
+
+static int
+onefs_shadow_copy_mknod(vfs_handle_struct *handle, const char *path,
+			mode_t mode, SMB_DEV_T dev)
+{
+	SHADOW_NEXT(MKNOD,
+		    (handle, cpath ?: path, mode, dev),
+		    int);
+}
+
+static char *
+onefs_shadow_copy_realpath(vfs_handle_struct *handle, const char *path,
+			   char *resolved_path)
+{
+	SHADOW_NEXT(REALPATH,
+		    (handle, cpath ?: path, resolved_path),
+		    char *);
+}
+
+static int onefs_shadow_copy_chflags(struct vfs_handle_struct *handle,
+				     const char *path, unsigned int flags)
+{
+	SHADOW_NEXT(CHFLAGS,
+		    (handle, cpath ?: path, flags),
+		    int);
+}
+
+static NTSTATUS
+onefs_shadow_copy_streaminfo(struct vfs_handle_struct *handle,
+			     struct files_struct *fsp,
+			     const char *path,
+			     TALLOC_CTX *mem_ctx,
+			     unsigned int *num_streams,
+			     struct stream_struct **streams)
+{
+	SHADOW_NEXT(STREAMINFO,
+		    (handle, fsp, cpath ?: path, mem_ctx, num_streams,
+			streams),
+		    NTSTATUS);
+}
+
+static int
+onefs_shadow_copy_get_real_filename(struct vfs_handle_struct *handle,
+				    const char *full_path,
+				    const char *path,
+				    TALLOC_CTX *mem_ctx,
+				    char **found_name)
+{
+	SHADOW_NEXT(GET_REAL_FILENAME,
+		    (handle, full_path, cpath ?: path, mem_ctx, found_name),
+		    int);
+}
+
+static NTSTATUS
+onefs_shadow_copy_get_nt_acl(struct vfs_handle_struct *handle,
+			    const char *path, uint32 security_info,
+			    struct security_descriptor **ppdesc)
+{
+	SHADOW_NEXT(GET_NT_ACL,
+		    (handle, cpath ?: path, security_info, ppdesc),
+		    NTSTATUS);
+}
+
+static int
+onefs_shadow_copy_chmod_acl(vfs_handle_struct *handle, const char *path,
+			    mode_t mode)
+{
+	SHADOW_NEXT(CHMOD_ACL,
+		    (handle, cpath ?: path, mode),
+		    int);
+}
+
+static SMB_ACL_T
+onefs_shadow_copy_sys_acl_get_file(vfs_handle_struct *handle,
+				   const char *path, SMB_ACL_TYPE_T type)
+{
+	SHADOW_NEXT(SYS_ACL_GET_FILE,
+		    (handle, cpath ?: path, type),
+		    SMB_ACL_T);
+}
+
+static int
+onefs_shadow_copy_sys_acl_set_file(vfs_handle_struct *handle, const char *path,
+				   SMB_ACL_TYPE_T type, SMB_ACL_T theacl)
+{
+	SHADOW_NEXT(SYS_ACL_SET_FILE,
+		    (handle, cpath ?: path, type, theacl),
+		    int);
+}
+
+static int
+onefs_shadow_copy_sys_acl_delete_def_file(vfs_handle_struct *handle,
+					  const char *path)
+{
+	SHADOW_NEXT(SYS_ACL_DELETE_DEF_FILE,
+		    (handle, cpath ?: path),
+		    int);
+}
+
+static ssize_t
+onefs_shadow_copy_getxattr(vfs_handle_struct *handle, const char *path,
+			   const char *name, void *value, size_t size)
+{
+	SHADOW_NEXT(GETXATTR,
+		    (handle, cpath ?: path, name, value, size),
+		    ssize_t);
+}
+
+static ssize_t
+onefs_shadow_copy_lgetxattr(vfs_handle_struct *handle, const char *path,
+			    const char *name, void *value, size_t size)
+{
+	SHADOW_NEXT(LGETXATTR,
+		    (handle, cpath ?: path, name, value, size),
+		    ssize_t);
+}
+
+static ssize_t
+onefs_shadow_copy_listxattr(vfs_handle_struct *handle, const char *path,
+			    char *list, size_t size)
+{
+	SHADOW_NEXT(LISTXATTR,
+		    (handle, cpath ?: path, list, size),
+		    ssize_t);
+}
+
+static ssize_t
+onefs_shadow_copy_llistxattr(vfs_handle_struct *handle, const char *path,
+			     char *list, size_t size)
+{
+	SHADOW_NEXT(LLISTXATTR,
+		    (handle, cpath ?: path, list, size),
+		    ssize_t);
+}
+
+static int
+onefs_shadow_copy_removexattr(vfs_handle_struct *handle, const char *path,
+			      const char *name)
+{
+	SHADOW_NEXT(REMOVEXATTR,
+		    (handle, cpath ?: path, name),
+		    int);
+}
+
+static int
+onefs_shadow_copy_lremovexattr(vfs_handle_struct *handle, const char *path,
+			       const char *name)
+{
+	SHADOW_NEXT(LREMOVEXATTR,
+		    (handle, cpath ?: path, name),
+		    int);
+}
+
+static int
+onefs_shadow_copy_setxattr(vfs_handle_struct *handle, const char *path,
+			   const char *name, const void *value, size_t size,
+			   int flags)
+{
+	SHADOW_NEXT(SETXATTR,
+		    (handle, cpath ?: path, name, value, size, flags),
+		    int);
+}
+
+static int
+onefs_shadow_copy_lsetxattr(vfs_handle_struct *handle, const char *path,
+			    const char *name, const void *value, size_t size,
+			    int flags)
+{
+	SHADOW_NEXT(LSETXATTR,
+		    (handle, cpath ?: path, name, value, size, flags),
+		    int);
+}
+
+static bool
+onefs_shadow_copy_is_offline(struct vfs_handle_struct *handle,
+			     const char *path, SMB_STRUCT_STAT *sbuf)
+{
+	SHADOW_NEXT(IS_OFFLINE,
+		    (handle, cpath ?: path, sbuf),
+		    bool);
+}
+
+static int
+onefs_shadow_copy_set_offline(struct vfs_handle_struct *handle,
+			      const char *path)
+{
+	SHADOW_NEXT(SET_OFFLINE,
+		    (handle, cpath ?: path),
+		    int);
+}
+
+/* VFS operations structure */
+
+static vfs_op_tuple onefs_shadow_copy_ops[] = {
+
+	/* Disk operations */
+
+	{SMB_VFS_OP(onefs_shadow_copy_disk_free), SMB_VFS_OP_DISK_FREE,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_get_shadow_copy_data),
+	 SMB_VFS_OP_GET_SHADOW_COPY_DATA, SMB_VFS_LAYER_OPAQUE},
+	{SMB_VFS_OP(onefs_shadow_copy_statvfs), SMB_VFS_OP_STATVFS,
+	 SMB_VFS_LAYER_TRANSPARENT},
+
+	/* Directory operations */
+
+	{SMB_VFS_OP(onefs_shadow_copy_opendir), SMB_VFS_OP_OPENDIR,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_mkdir), SMB_VFS_OP_MKDIR,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_rmdir), SMB_VFS_OP_RMDIR,
+	 SMB_VFS_LAYER_TRANSPARENT},
+
+	/* File operations */
+
+	{SMB_VFS_OP(onefs_shadow_copy_open), SMB_VFS_OP_OPEN,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_create_file), SMB_VFS_OP_CREATE_FILE,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_rename), SMB_VFS_OP_RENAME,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_stat), SMB_VFS_OP_STAT,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_stat), SMB_VFS_OP_STAT,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_lstat), SMB_VFS_OP_LSTAT,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_unlink), SMB_VFS_OP_UNLINK,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_chmod), SMB_VFS_OP_CHMOD,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_chown), SMB_VFS_OP_CHOWN,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_lchown), SMB_VFS_OP_LCHOWN,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_chdir), SMB_VFS_OP_CHDIR,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_ntimes), SMB_VFS_OP_NTIMES,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_symlink), SMB_VFS_OP_SYMLINK,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_readlink), SMB_VFS_OP_READLINK,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_link), SMB_VFS_OP_LINK,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_mknod), SMB_VFS_OP_MKNOD,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_realpath), SMB_VFS_OP_REALPATH,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_chflags), SMB_VFS_OP_CHFLAGS,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_streaminfo), SMB_VFS_OP_STREAMINFO,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_get_real_filename),
+	 SMB_VFS_OP_GET_REAL_FILENAME, SMB_VFS_LAYER_TRANSPARENT},
+
+	/* NT File ACL operations */
+
+	{SMB_VFS_OP(onefs_shadow_copy_get_nt_acl), SMB_VFS_OP_GET_NT_ACL,
+	 SMB_VFS_LAYER_TRANSPARENT},
+
+	/* POSIX ACL operations */
+
+	{SMB_VFS_OP(onefs_shadow_copy_chmod_acl), SMB_VFS_OP_CHMOD_ACL,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_sys_acl_get_file),
+	 SMB_VFS_OP_SYS_ACL_GET_FILE, SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_sys_acl_set_file),
+	 SMB_VFS_OP_SYS_ACL_SET_FILE, SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_sys_acl_delete_def_file),
+	 SMB_VFS_OP_SYS_ACL_DELETE_DEF_FILE, SMB_VFS_LAYER_TRANSPARENT},
+
+        /* EA operations. */
+
+	{SMB_VFS_OP(onefs_shadow_copy_getxattr), SMB_VFS_OP_GETXATTR,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_lgetxattr), SMB_VFS_OP_LGETXATTR,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_listxattr), SMB_VFS_OP_LISTXATTR,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_llistxattr), SMB_VFS_OP_LLISTXATTR,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_removexattr), SMB_VFS_OP_REMOVEXATTR,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_lremovexattr), SMB_VFS_OP_LREMOVEXATTR,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_setxattr), SMB_VFS_OP_SETXATTR,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_lsetxattr), SMB_VFS_OP_LSETXATTR,
+	 SMB_VFS_LAYER_TRANSPARENT},
+
+	/* offline operations */
+	{SMB_VFS_OP(onefs_shadow_copy_is_offline), SMB_VFS_OP_IS_OFFLINE,
+	 SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(onefs_shadow_copy_set_offline), SMB_VFS_OP_SET_OFFLINE,
+	 SMB_VFS_LAYER_TRANSPARENT},
+
+	{SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP}
+};
+
+NTSTATUS vfs_shadow_copy_init(void)
+{
+	NTSTATUS ret;
+
+	ret = smb_register_vfs(SMB_VFS_INTERFACE_VERSION,
+			       "onefs_shadow_copy",
+			       onefs_shadow_copy_ops);
+
+	if (!NT_STATUS_IS_OK(ret))
+		return ret;
+
+	vfs_onefs_shadow_copy_debug_level = debug_add_class("onefs_shadow_copy");
+
+	if (vfs_onefs_shadow_copy_debug_level == -1) {
+		vfs_onefs_shadow_copy_debug_level = DBGC_VFS;
+		DEBUG(0, ("Couldn't register custom debugging class!\n"));
+	} else {
+		DEBUG(10, ("Debug class number of 'onefs_shadow_copy': %d\n",
+			   vfs_onefs_shadow_copy_debug_level));
+	}
+
+	return ret;
+}