Revert "overlay: simplify and adapt to "overlay""

src/lxc/bdev/bdev.c

@@ -194,7 +194,6 @@ static const struct bdev_type bdevs[] = {
 	{ .name = "btrfs",     .ops = &btrfs_ops, },
 	{ .name = "dir",       .ops = &dir_ops,   },
 	{ .name = "aufs",      .ops = &aufs_ops,  },
-	{ .name = "overlay",   .ops = &ovl_ops,   },
 	{ .name = "overlayfs", .ops = &ovl_ops,   },
 	{ .name = "loop",      .ops = &loop_ops,  },
 	{ .name = "nbd",       .ops = &nbd_ops,   },
@@ -375,11 +374,10 @@ struct bdev *bdev_copy(struct lxc_container *c0, const char *cname,
 	 */
 	if (!bdevtype && !keepbdevtype && snap &&
 	    strcmp(orig->type, "dir") == 0)
-		bdevtype = "overlay";
+		bdevtype = "overlayfs";
 
 	if (am_unpriv() && !unpriv_snap_allowed(orig, bdevtype, snap, maybe_snap)) {
-		ERROR("Unsupported snapshot type \"%s\" for unprivileged users",
-		      bdevtype ? bdevtype : "(null)");
+		ERROR("Unsupported snapshot type for unprivileged users");
 		bdev_put(orig);
 		return NULL;
 	}
@@ -387,8 +385,7 @@ struct bdev *bdev_copy(struct lxc_container *c0, const char *cname,
 	*needs_rdep = 0;
 	if (bdevtype && strcmp(orig->type, "dir") == 0 &&
 	    (strcmp(bdevtype, "aufs") == 0 ||
-	     strcmp(bdevtype, "overlayfs") == 0 ||
-	     strcmp(bdevtype, "overlay") == 0)) {
+	     strcmp(bdevtype, "overlayfs") == 0)) {
 		*needs_rdep = 1;
 	} else if (snap && strcmp(orig->type, "lvm") == 0 &&
 		   !lvm_is_thin_volume(orig->src)) {
@@ -414,10 +411,8 @@ struct bdev *bdev_copy(struct lxc_container *c0, const char *cname,
 		goto err;
 	}
 
-	if (!strcmp(new->type, "overlay") || !strcmp(new->type, "overlayfs"))
-		src_no_prefix = ovl_get_lower(new->src);
-	else
-		src_no_prefix = lxc_storage_get_path(new->src, new->type);
+	src_no_prefix = lxc_storage_get_path(new->src, new->type);
+
 	if (am_unpriv() && chown_mapped_root(src_no_prefix, c0->lxc_conf) < 0)
 		WARN("Failed to update ownership of %s", new->dest);
 

src/lxc/bdev/lxcoverlay.c

@@ -34,7 +34,6 @@
 #include "lxccontainer.h"
 #include "lxcoverlay.h"
 #include "lxcrsync.h"
-#include "storage_utils.h"
 #include "utils.h"
 
 lxc_log_define(lxcoverlay, lxc);
@@ -42,6 +41,10 @@ lxc_log_define(lxcoverlay, lxc);
 static char *ovl_name;
 static char *ovl_version[] = {"overlay", "overlayfs"};
 
+/* defined in lxccontainer.c: needs to become common helper */
+extern char *dir_new_path(char *src, const char *oldname, const char *name,
+			  const char *oldpath, const char *lxcpath);
+
 static char *ovl_detect_name(void);
 static int ovl_do_rsync(struct bdev *orig, struct bdev *new,
 			struct lxc_conf *conf);
@@ -58,18 +61,16 @@ int ovl_clonepaths(struct bdev *orig, struct bdev *new, const char *oldname,
         char *src;
 
 	if (!snap) {
-		ERROR("overlay is only for snapshot clones");
+		ERROR("overlayfs is only for snapshot clones");
 		return -22;
 	}
 
 	if (!orig->src || !orig->dest)
 		return -1;
 
-	new->dest = lxc_string_join(
-	    "/", (const char *[]){lxcpath, cname, "rootfs", NULL}, false);
+	new->dest = dir_new_path(orig->dest, oldname, cname, oldpath, lxcpath);
 	if (!new->dest)
 		return -1;
-
 	if (mkdir_p(new->dest, 0755) < 0)
 		return -1;
 
@@ -142,11 +143,11 @@ int ovl_clonepaths(struct bdev *orig, struct bdev *new, const char *oldname,
 			free(delta);
 			return -ENOMEM;
 		}
-		ret = snprintf(new->src, len, "overlay:%s:%s", src, delta);
+		ret = snprintf(new->src, len, "overlayfs:%s:%s", src, delta);
 		free(delta);
 		if (ret < 0 || ret >= len)
-			return -1;
-	} else if (!strcmp(orig->type, "overlayfs") || !strcmp(orig->type, "overlay")) {
+			return -ENOMEM;
+	} else if (strcmp(orig->type, "overlayfs") == 0) {
 		/*
 		 * What exactly do we want to do here?  I think we want to use
 		 * the original lowerdir, with a private delta which is
@@ -155,44 +156,26 @@ int ovl_clonepaths(struct bdev *orig, struct bdev *new, const char *oldname,
 		char *osrc, *odelta, *nsrc, *ndelta, *work;
 		char *lastslash;
 		int len, ret, lastslashidx;
-
-		osrc = strdup(orig->src);
-		if (!osrc) {
-                        SYSERROR("Failed to duplicate \"%s\"", orig->src);
+		if (!(osrc = strdup(orig->src)))
 			return -22;
-                }
-
 		nsrc = strchr(osrc, ':') + 1;
-		if ((nsrc != osrc + 8) && (nsrc != osrc + 10)) {
-			free(osrc);
-                        ERROR("Detected \":\" in \"%s\" at wrong position", osrc);
-			return -22;
-                }
-
-		odelta = strchr(nsrc, ':');
-		if (!odelta) {
+		if (nsrc != osrc + 10 || (odelta = strchr(nsrc, ':')) == NULL) {
 			free(osrc);
-                        ERROR("Failed to find \":\" in \"%s\"", nsrc);
 			return -22;
 		}
-
 		*odelta = '\0';
 		odelta++;
-                ndelta = lxc_string_join("/", (const char *[]){lxcpath, cname, "rootfs", NULL}, false);
-                if (!ndelta) {
+		ndelta = dir_new_path(odelta, oldname, cname, oldpath, lxcpath);
+		if (!ndelta) {
 			free(osrc);
-                        ERROR("Failed to create new path");
 			return -ENOMEM;
-                }
-
-		ret = mkdir(ndelta, 0755);
-		if (ret < 0 && errno != EEXIST) {
+		}
+		if ((ret = mkdir(ndelta, 0755)) < 0 && errno != EEXIST) {
+			SYSERROR("error: mkdir %s", ndelta);
 			free(osrc);
 			free(ndelta);
-			SYSERROR("Failed to create \"%s\"", ndelta);
 			return -1;
 		}
-
 		if (am_unpriv() && chown_mapped_root(ndelta, conf) < 0)
 			WARN("Failed to update ownership of %s", ndelta);
 
@@ -204,7 +187,6 @@ int ovl_clonepaths(struct bdev *orig, struct bdev *new, const char *oldname,
 		if (!lastslash) {
 			free(osrc);
 			free(ndelta);
-			ERROR("Failed to detect \"/\" in \"%s\"", ndelta);
 			return -1;
 		}
 		lastslash++;
@@ -214,43 +196,37 @@ int ovl_clonepaths(struct bdev *orig, struct bdev *new, const char *oldname,
 		if (!work) {
 			free(osrc);
 			free(ndelta);
-			ERROR("Failed to allocate memory");
 			return -1;
 		}
 		strncpy(work, ndelta, lastslashidx + 1);
 		strcpy(work + lastslashidx, "olwork");
-		ret = mkdir(work, 0755);
-		if (ret < 0 && errno != EEXIST) {
+		if ((mkdir(work, 0755) < 0) && errno != EEXIST) {
+			SYSERROR("error: mkdir %s", work);
 			free(osrc);
 			free(ndelta);
 			free(work);
-			SYSERROR("Failed to create \"%s\"", ndelta);
 			return -1;
 		}
-
 		if (am_unpriv() && chown_mapped_root(work, conf) < 0)
 			WARN("Failed to update ownership of %s", work);
 		free(work);
 
-		len = strlen(nsrc) + strlen(ndelta) + 10;
+		len = strlen(nsrc) + strlen(ndelta) + 12;
 		new->src = malloc(len);
 		if (!new->src) {
 			free(osrc);
 			free(ndelta);
-			ERROR("Failed to allocate memory");
 			return -ENOMEM;
 		}
-		ret = snprintf(new->src, len, "overlay:%s:%s", nsrc, ndelta);
+		ret = snprintf(new->src, len, "overlayfs:%s:%s", nsrc, ndelta);
 		free(osrc);
 		free(ndelta);
-		if (ret < 0 || ret >= len) {
-			ERROR("Failed to create string");
-			return -1;
-                }
+		if (ret < 0 || ret >= len)
+			return -ENOMEM;
 
 		return ovl_do_rsync(orig, new, conf);
 	} else {
-		ERROR("overlay clone of %s container is not yet supported",
+		ERROR("overlayfs clone of %s container is not yet supported",
 		      orig->type);
 		/*
 		 * Note, supporting this will require ovl_mount supporting
@@ -263,7 +239,7 @@ int ovl_clonepaths(struct bdev *orig, struct bdev *new, const char *oldname,
 }
 
 /*
- * to say 'lxc-create -t ubuntu -n o1 -B overlay' means you want
+ * to say 'lxc-create -t ubuntu -n o1 -B overlayfs' means you want
  * $lxcpath/$lxcname/rootfs to have the created container, while all
  * changes after starting the container are written to
  * $lxcpath/$lxcname/delta0
@@ -291,14 +267,14 @@ int ovl_create(struct bdev *bdev, const char *dest, const char *n,
 		return -1;
 	}
 
-	// overlay:lower:upper
-	newlen = (2 * len) + strlen("overlay:") + 2;
+	// overlayfs:lower:upper
+	newlen = (2 * len) + strlen("overlayfs:") + 2;
 	bdev->src = malloc(newlen);
 	if (!bdev->src) {
 		ERROR("Out of memory");
 		return -1;
 	}
-	ret = snprintf(bdev->src, newlen, "overlay:%s:%s", dest, delta);
+	ret = snprintf(bdev->src, newlen, "overlayfs:%s:%s", dest, delta);
 	if (ret < 0 || ret >= newlen)
 		return -1;
 
@@ -312,23 +288,14 @@ int ovl_create(struct bdev *bdev, const char *dest, const char *n,
 
 int ovl_destroy(struct bdev *orig)
 {
-        bool ovl;
-	char *upper = orig->src;
+	char *upper;
 
-        ovl = !strncmp(upper, "overlay:", 8);
-	if (!ovl && strncmp(upper, "overlayfs:", 10))
+	if (strncmp(orig->src, "overlayfs:", 10) != 0)
 		return -22;
-
-        if (ovl)
-                upper += 8;
-        else
-                upper += 10;
-
-	upper = strchr(upper, ':');
+	upper = strchr(orig->src + 10, ':');
 	if (!upper)
 		return -22;
 	upper++;
-
 	return lxc_rmdir_onedev(upper, NULL);
 }
 
@@ -339,6 +306,14 @@ int ovl_detect(const char *path)
 	return 0;
 }
 
+char *ovl_getlower(char *p)
+{
+	char *p1 = strchr(p, ':');
+	if (p1)
+		*p1 = '\0';
+	return p;
+}
+
 int ovl_mount(struct bdev *bdev)
 {
 	char *tmp, *options, *dup, *lower, *upper;
@@ -349,9 +324,8 @@ int ovl_mount(struct bdev *bdev)
 	char *mntdata;
 	int ret, ret2;
 
-	if (strcmp(bdev->type, "overlay") && strcmp(bdev->type, "overlayfs"))
+	if (strcmp(bdev->type, "overlayfs"))
 		return -22;
-
 	if (!bdev->src || !bdev->dest)
 		return -22;
 
@@ -445,7 +419,7 @@ int ovl_mount(struct bdev *bdev)
 	ret = ovl_remount_on_enodev(lower, bdev->dest, ovl_name,
 				    MS_MGC_VAL | mntflags, options_work);
 	if (ret < 0) {
-		INFO("Overlay: Error mounting %s onto %s with options %s. "
+		INFO("Overlayfs: Error mounting %s onto %s with options %s. "
 		     "Retrying without workdir: %s.",
 		     lower, bdev->dest, options_work, strerror(errno));
 
@@ -453,15 +427,15 @@ int ovl_mount(struct bdev *bdev)
 		ret = ovl_remount_on_enodev(lower, bdev->dest, ovl_name,
 					  MS_MGC_VAL | mntflags, options);
 		if (ret < 0)
-			SYSERROR("Overlay: Error mounting %s onto %s with "
+			SYSERROR("Overlayfs: Error mounting %s onto %s with "
 				 "options %s: %s.",
 				 lower, bdev->dest, options,
 				 strerror(errno));
 		else
-			INFO("Overlay: Mounted %s onto %s with options %s.",
+			INFO("Overlayfs: Mounted %s onto %s with options %s.",
 			     lower, bdev->dest, options);
 	} else {
-		INFO("Overlay: Mounted %s onto %s with options %s.", lower,
+		INFO("Overlayfs: Mounted %s onto %s with options %s.", lower,
 		     bdev->dest, options_work);
 	}
 	return ret;
@@ -469,31 +443,13 @@ int ovl_mount(struct bdev *bdev)
 
 int ovl_umount(struct bdev *bdev)
 {
-	if (strcmp(bdev->type, "overlay") && strcmp(bdev->type, "overlayfs"))
+	if (strcmp(bdev->type, "overlayfs"))
 		return -22;
-
 	if (!bdev->src || !bdev->dest)
 		return -22;
-
 	return umount(bdev->dest);
 }
 
-char *ovl_get_lower(const char *rootfs_path)
-{
-	char *s1;
-	s1 = strstr(rootfs_path, ":/");
-	if (!s1)
-		return NULL;
-	s1++;
-
-	s1 = strstr(s1, ":/");
-	if (!s1)
-		return NULL;
-	s1++;
-
-	return s1;
-}
-
 char *ovl_get_rootfs(const char *rootfs_path, size_t *rootfslen)
 {
 	char *rootfsdir = NULL;
@@ -802,7 +758,7 @@ static int ovl_do_rsync(struct bdev *orig, struct bdev *new, struct lxc_conf *co
 	else
 		ret = ovl_rsync(&rdata);
 	if (ret)
-		ERROR("copying overlay delta");
+		ERROR("copying overlayfs delta");
 
 	return ret;
 }

src/lxc/bdev/lxcoverlay.h

@@ -76,7 +76,7 @@ int ovl_update_abs_paths(struct lxc_conf *lxc_conf, const char *lxc_path,
  * To be called from functions in lxccontainer.c: Get lower directory for
  * overlay rootfs.
  */
-char *ovl_get_lower(const char *rootfs_path);
+char *ovl_getlower(char *p);
 
 /*
  * Get rootfs path for overlay backed containers. Allocated memory must be freed

src/lxc/bdev/storage_utils.c

@@ -415,7 +415,6 @@ bool unpriv_snap_allowed(struct bdev *b, const char *t, bool snap,
 		// overlayfs -- which is also allowed)
 		if (strcmp(b->type, "dir") == 0 ||
 		    strcmp(b->type, "aufs") == 0 ||
-		    strcmp(b->type, "overlay") == 0 ||
 		    strcmp(b->type, "overlayfs") == 0 ||
 		    strcmp(b->type, "btrfs") == 0 ||
 		    strcmp(b->type, "loop") == 0)
@@ -428,7 +427,6 @@ bool unpriv_snap_allowed(struct bdev *b, const char *t, bool snap,
 	// and loop.  In particular, not zfs, btrfs, or lvm.
 	if (strcmp(t, "dir") == 0 ||
 	    strcmp(t, "aufs") == 0 ||
-	    strcmp(t, "overlay") == 0 ||
 	    strcmp(t, "overlayfs") == 0 ||
 	    strcmp(t, "btrfs") == 0 ||
 	    strcmp(t, "loop") == 0)

src/lxc/conf.c

@@ -3623,6 +3623,7 @@ int chown_mapped_root(char *path, struct lxc_conf *conf)
 {
 	uid_t rootuid, rootgid;
 	unsigned long val;
+	char *chownpath = path;
 	int hostuid, hostgid, ret;
 	struct stat sb;
 	char map1[100], map2[100], map3[100], map4[100], map5[100];
@@ -3658,6 +3659,23 @@ int chown_mapped_root(char *path, struct lxc_conf *conf)
 	}
 	rootgid = (gid_t)val;
 
+	/*
+	 * In case of overlay, we want only the writeable layer to be chowned
+	 */
+	if (strncmp(path, "overlayfs:", 10) == 0 || strncmp(path, "aufs:", 5) == 0) {
+		chownpath = strchr(path, ':');
+		if (!chownpath) {
+			ERROR("Bad overlay path: %s", path);
+			return -1;
+		}
+		chownpath = strchr(chownpath + 1, ':');
+		if (!chownpath) {
+			ERROR("Bad overlay path: %s", path);
+			return -1;
+		}
+		chownpath++;
+	}
+	path = chownpath;
 	if (hostuid == 0) {
 		if (chown(path, rootuid, rootgid) < 0) {
 			ERROR("Error chowning %s", path);

src/lxc/lxccontainer.c

@@ -3225,8 +3225,8 @@ static int clone_update_rootfs_wrapper(void *data)
 sudo lxc-clone -o o1 -n n1 -s -L|-fssize fssize -v|--vgname vgname \
         -p|--lvprefix lvprefix -t|--fstype fstype  -B backingstore
 
--s [ implies overlay]
--s -B overlay
+-s [ implies overlayfs]
+-s -B overlayfs
 -s -B aufs
 
 only rootfs gets converted (copied/snapshotted) on clone.
@@ -3600,7 +3600,7 @@ static int do_lxcapi_snapshot(struct lxc_container *c, const char *commentfile)
 	if (bdev_is_dir(c->lxc_conf, c->lxc_conf->rootfs.path)) {
 		ERROR("Snapshot of directory-backed container requested.");
 		ERROR("Making a copy-clone.  If you do want snapshots, then");
-		ERROR("please create an aufs or overlay clone first, snapshot that");
+		ERROR("please create an aufs or overlayfs clone first, snapshot that");
 		ERROR("and keep the original container pristine.");
 		flags &= ~LXC_CLONE_SNAPSHOT | LXC_CLONE_MAYBE_SNAPSHOT;
 	}