Merge tag 'ovl-update-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs update from Miklos Szeredi:

 - Try to preserve holes in sparse files when copying up, thus saving
   disk space and improving performance.

 - Fix a performance regression introduced in v4.19 by preserving
   asynchronicity of IO when fowarding to underlying layers. Add VFS
   helpers to submit async iocbs.

 - Fix a regression in lseek(2) introduced in v4.19 that breaks >2G
   seeks on 32bit kernels.

 - Fix a corner case where st_ino/st_dev was not preserved across copy
   up.

 - Miscellaneous fixes and cleanups.

* tag 'ovl-update-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: fix lseek overflow on 32bit
  ovl: add splice file read write helper
  ovl: implement async IO routines
  vfs: add vfs_iocb_iter_[read|write] helper functions
  ovl: layer is const
  ovl: fix corner case of non-constant st_dev;st_ino
  ovl: fix corner case of conflicting lower layer uuid
  ovl: generalize the lower_fs[] array
  ovl: simplify ovl_same_sb() helper
  ovl: generalize the lower_layers[] array
  ovl: improving copy-up efficiency for big sparse file
  ovl: use ovl_inode_lock in ovl_llseek()
  ovl: use pr_fmt auto generate prefix
  ovl: fix wrong WARN_ON() in ovl_cache_update_ino()

1 files changed, 130 insertions, 103 deletions

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 7621ff176d15..319fe0d355b0 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -224,14 +224,14 @@ static void ovl_free_fs(struct ovl_fs *ofs)
 	if (ofs->upperdir_locked)
 		ovl_inuse_unlock(ofs->upper_mnt->mnt_root);
 	mntput(ofs->upper_mnt);
-	for (i = 0; i < ofs->numlower; i++) {
-		iput(ofs->lower_layers[i].trap);
-		mntput(ofs->lower_layers[i].mnt);
+	for (i = 1; i < ofs->numlayer; i++) {
+		iput(ofs->layers[i].trap);
+		mntput(ofs->layers[i].mnt);
 	}
-	for (i = 0; i < ofs->numlowerfs; i++)
-		free_anon_bdev(ofs->lower_fs[i].pseudo_dev);
-	kfree(ofs->lower_layers);
-	kfree(ofs->lower_fs);
+	kfree(ofs->layers);
+	for (i = 0; i < ofs->numfs; i++)
+		free_anon_bdev(ofs->fs[i].pseudo_dev);
+	kfree(ofs->fs);
 
 	kfree(ofs->config.lowerdir);
 	kfree(ofs->config.upperdir);
@@ -358,7 +358,7 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry)
 	if (ofs->config.nfs_export != ovl_nfs_export_def)
 		seq_printf(m, ",nfs_export=%s", ofs->config.nfs_export ?
 						"on" : "off");
-	if (ofs->config.xino != ovl_xino_def())
+	if (ofs->config.xino != ovl_xino_def() && !ovl_same_fs(sb))
 		seq_printf(m, ",xino=%s", ovl_xino_str[ofs->config.xino]);
 	if (ofs->config.metacopy != ovl_metacopy_def)
 		seq_printf(m, ",metacopy=%s",
@@ -462,7 +462,7 @@ static int ovl_parse_redirect_mode(struct ovl_config *config, const char *mode)
 		if (ovl_redirect_always_follow)
 			config->redirect_follow = true;
 	} else if (strcmp(mode, "nofollow") != 0) {
-		pr_err("overlayfs: bad mount option \"redirect_dir=%s\"\n",
+		pr_err("bad mount option \"redirect_dir=%s\"\n",
 		       mode);
 		return -EINVAL;
 	}
@@ -560,14 +560,15 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
 			break;
 
 		default:
-			pr_err("overlayfs: unrecognized mount option \"%s\" or missing value\n", p);
+			pr_err("unrecognized mount option \"%s\" or missing value\n",
+					p);
 			return -EINVAL;
 		}
 	}
 
 	/* Workdir is useless in non-upper mount */
 	if (!config->upperdir && config->workdir) {
-		pr_info("overlayfs: option \"workdir=%s\" is useless in a non-upper mount, ignore\n",
+		pr_info("option \"workdir=%s\" is useless in a non-upper mount, ignore\n",
 			config->workdir);
 		kfree(config->workdir);
 		config->workdir = NULL;
@@ -587,7 +588,7 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
 	/* Resolve metacopy -> redirect_dir dependency */
 	if (config->metacopy && !config->redirect_dir) {
 		if (metacopy_opt && redirect_opt) {
-			pr_err("overlayfs: conflicting options: metacopy=on,redirect_dir=%s\n",
+			pr_err("conflicting options: metacopy=on,redirect_dir=%s\n",
 			       config->redirect_mode);
 			return -EINVAL;
 		}
@@ -596,7 +597,7 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
 			 * There was an explicit redirect_dir=... that resulted
 			 * in this conflict.
 			 */
-			pr_info("overlayfs: disabling metacopy due to redirect_dir=%s\n",
+			pr_info("disabling metacopy due to redirect_dir=%s\n",
 				config->redirect_mode);
 			config->metacopy = false;
 		} else {
@@ -692,7 +693,7 @@ out_unlock:
 out_dput:
 	dput(work);
 out_err:
-	pr_warn("overlayfs: failed to create directory %s/%s (errno: %i); mounting read-only\n",
+	pr_warn("failed to create directory %s/%s (errno: %i); mounting read-only\n",
 		ofs->config.workdir, name, -err);
 	work = NULL;
 	goto out_unlock;
@@ -716,21 +717,21 @@ static int ovl_mount_dir_noesc(const char *name, struct path *path)
 	int err = -EINVAL;
 
 	if (!*name) {
-		pr_err("overlayfs: empty lowerdir\n");
+		pr_err("empty lowerdir\n");
 		goto out;
 	}
 	err = kern_path(name, LOOKUP_FOLLOW, path);
 	if (err) {
-		pr_err("overlayfs: failed to resolve '%s': %i\n", name, err);
+		pr_err("failed to resolve '%s': %i\n", name, err);
 		goto out;
 	}
 	err = -EINVAL;
 	if (ovl_dentry_weird(path->dentry)) {
-		pr_err("overlayfs: filesystem on '%s' not supported\n", name);
+		pr_err("filesystem on '%s' not supported\n", name);
 		goto out_put;
 	}
 	if (!d_is_dir(path->dentry)) {
-		pr_err("overlayfs: '%s' not a directory\n", name);
+		pr_err("'%s' not a directory\n", name);
 		goto out_put;
 	}
 	return 0;
@@ -752,7 +753,7 @@ static int ovl_mount_dir(const char *name, struct path *path)
 
 		if (!err)
 			if (ovl_dentry_remote(path->dentry)) {
-				pr_err("overlayfs: filesystem on '%s' not supported as upperdir\n",
+				pr_err("filesystem on '%s' not supported as upperdir\n",
 				       tmp);
 				path_put_init(path);
 				err = -EINVAL;
@@ -769,7 +770,7 @@ static int ovl_check_namelen(struct path *path, struct ovl_fs *ofs,
 	int err = vfs_statfs(path, &statfs);
 
 	if (err)
-		pr_err("overlayfs: statfs failed on '%s'\n", name);
+		pr_err("statfs failed on '%s'\n", name);
 	else
 		ofs->namelen = max(ofs->namelen, statfs.f_namelen);
 
@@ -804,13 +805,13 @@ static int ovl_lower_dir(const char *name, struct path *path,
 	     (ofs->config.index && ofs->config.upperdir)) && !fh_type) {
 		ofs->config.index = false;
 		ofs->config.nfs_export = false;
-		pr_warn("overlayfs: fs on '%s' does not support file handles, falling back to index=off,nfs_export=off.\n",
+		pr_warn("fs on '%s' does not support file handles, falling back to index=off,nfs_export=off.\n",
 			name);
 	}
 
 	/* Check if lower fs has 32bit inode numbers */
 	if (fh_type != FILEID_INO32_GEN)
-		ofs->xino_bits = 0;
+		ofs->xino_mode = -1;
 
 	return 0;
 
@@ -996,7 +997,7 @@ static int ovl_setup_trap(struct super_block *sb, struct dentry *dir,
 	err = PTR_ERR_OR_ZERO(trap);
 	if (err) {
 		if (err == -ELOOP)
-			pr_err("overlayfs: conflicting %s path\n", name);
+			pr_err("conflicting %s path\n", name);
 		return err;
 	}
 
@@ -1013,11 +1014,11 @@ static int ovl_setup_trap(struct super_block *sb, struct dentry *dir,
 static int ovl_report_in_use(struct ovl_fs *ofs, const char *name)
 {
 	if (ofs->config.index) {
-		pr_err("overlayfs: %s is in-use as upperdir/workdir of another mount, mount with '-o index=off' to override exclusive upperdir protection.\n",
+		pr_err("%s is in-use as upperdir/workdir of another mount, mount with '-o index=off' to override exclusive upperdir protection.\n",
 		       name);
 		return -EBUSY;
 	} else {
-		pr_warn("overlayfs: %s is in-use as upperdir/workdir of another mount, accessing files from both mounts will result in undefined behavior.\n",
+		pr_warn("%s is in-use as upperdir/workdir of another mount, accessing files from both mounts will result in undefined behavior.\n",
 			name);
 		return 0;
 	}
@@ -1035,7 +1036,7 @@ static int ovl_get_upper(struct super_block *sb, struct ovl_fs *ofs,
 
 	/* Upper fs should not be r/o */
 	if (sb_rdonly(upperpath->mnt->mnt_sb)) {
-		pr_err("overlayfs: upper fs is r/o, try multi-lower layers mount\n");
+		pr_err("upper fs is r/o, try multi-lower layers mount\n");
 		err = -EINVAL;
 		goto out;
 	}
@@ -1052,7 +1053,7 @@ static int ovl_get_upper(struct super_block *sb, struct ovl_fs *ofs,
 	upper_mnt = clone_private_mount(upperpath);
 	err = PTR_ERR(upper_mnt);
 	if (IS_ERR(upper_mnt)) {
-		pr_err("overlayfs: failed to clone upperpath\n");
+		pr_err("failed to clone upperpath\n");
 		goto out;
 	}
 
@@ -1108,7 +1109,7 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
 	 * kernel upgrade. So warn instead of erroring out.
 	 */
 	if (!err)
-		pr_warn("overlayfs: upper fs needs to support d_type.\n");
+		pr_warn("upper fs needs to support d_type.\n");
 
 	/* Check if upper/work fs supports O_TMPFILE */
 	temp = ovl_do_tmpfile(ofs->workdir, S_IFREG | 0);
@@ -1116,7 +1117,7 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
 	if (ofs->tmpfile)
 		dput(temp);
 	else
-		pr_warn("overlayfs: upper fs does not support tmpfile.\n");
+		pr_warn("upper fs does not support tmpfile.\n");
 
 	/*
 	 * Check if upper/work fs supports trusted.overlay.* xattr
@@ -1126,7 +1127,7 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
 		ofs->noxattr = true;
 		ofs->config.index = false;
 		ofs->config.metacopy = false;
-		pr_warn("overlayfs: upper fs does not support xattr, falling back to index=off and metacopy=off.\n");
+		pr_warn("upper fs does not support xattr, falling back to index=off and metacopy=off.\n");
 		err = 0;
 	} else {
 		vfs_removexattr(ofs->workdir, OVL_XATTR_OPAQUE);
@@ -1136,16 +1137,16 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
 	fh_type = ovl_can_decode_fh(ofs->workdir->d_sb);
 	if (ofs->config.index && !fh_type) {
 		ofs->config.index = false;
-		pr_warn("overlayfs: upper fs does not support file handles, falling back to index=off.\n");
+		pr_warn("upper fs does not support file handles, falling back to index=off.\n");
 	}
 
 	/* Check if upper fs has 32bit inode numbers */
 	if (fh_type != FILEID_INO32_GEN)
-		ofs->xino_bits = 0;
+		ofs->xino_mode = -1;
 
 	/* NFS export of r/w mount depends on index */
 	if (ofs->config.nfs_export && !ofs->config.index) {
-		pr_warn("overlayfs: NFS export requires \"index=on\", falling back to nfs_export=off.\n");
+		pr_warn("NFS export requires \"index=on\", falling back to nfs_export=off.\n");
 		ofs->config.nfs_export = false;
 	}
 out:
@@ -1165,11 +1166,11 @@ static int ovl_get_workdir(struct super_block *sb, struct ovl_fs *ofs,
 
 	err = -EINVAL;
 	if (upperpath->mnt != workpath.mnt) {
-		pr_err("overlayfs: workdir and upperdir must reside under the same mount\n");
+		pr_err("workdir and upperdir must reside under the same mount\n");
 		goto out;
 	}
 	if (!ovl_workdir_ok(workpath.dentry, upperpath->dentry)) {
-		pr_err("overlayfs: workdir and upperdir must be separate subtrees\n");
+		pr_err("workdir and upperdir must be separate subtrees\n");
 		goto out;
 	}
 
@@ -1210,7 +1211,7 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs,
 	err = ovl_verify_origin(upperpath->dentry, oe->lowerstack[0].dentry,
 				true);
 	if (err) {
-		pr_err("overlayfs: failed to verify upper root origin\n");
+		pr_err("failed to verify upper root origin\n");
 		goto out;
 	}
 
@@ -1233,18 +1234,18 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs,
 			err = ovl_verify_set_fh(ofs->indexdir, OVL_XATTR_ORIGIN,
 						upperpath->dentry, true, false);
 			if (err)
-				pr_err("overlayfs: failed to verify index dir 'origin' xattr\n");
+				pr_err("failed to verify index dir 'origin' xattr\n");
 		}
 		err = ovl_verify_upper(ofs->indexdir, upperpath->dentry, true);
 		if (err)
-			pr_err("overlayfs: failed to verify index dir 'upper' xattr\n");
+			pr_err("failed to verify index dir 'upper' xattr\n");
 
 		/* Cleanup bad/stale/orphan index entries */
 		if (!err)
 			err = ovl_indexdir_cleanup(ofs);
 	}
 	if (err || !ofs->indexdir)
-		pr_warn("overlayfs: try deleting index dir or mounting with '-o index=off' to disable inodes index.\n");
+		pr_warn("try deleting index dir or mounting with '-o index=off' to disable inodes index.\n");
 
 out:
 	mnt_drop_write(mnt);
@@ -1258,7 +1259,7 @@ static bool ovl_lower_uuid_ok(struct ovl_fs *ofs, const uuid_t *uuid)
 	if (!ofs->config.nfs_export && !ofs->upper_mnt)
 		return true;
 
-	for (i = 0; i < ofs->numlowerfs; i++) {
+	for (i = 0; i < ofs->numfs; i++) {
 		/*
 		 * We use uuid to associate an overlay lower file handle with a
 		 * lower layer, so we can accept lower fs with null uuid as long
@@ -1266,8 +1267,9 @@ static bool ovl_lower_uuid_ok(struct ovl_fs *ofs, const uuid_t *uuid)
 		 * if we detect multiple lower fs with the same uuid, we
 		 * disable lower file handle decoding on all of them.
 		 */
-		if (uuid_equal(&ofs->lower_fs[i].sb->s_uuid, uuid)) {
-			ofs->lower_fs[i].bad_uuid = true;
+		if (ofs->fs[i].is_lower &&
+		    uuid_equal(&ofs->fs[i].sb->s_uuid, uuid)) {
+			ofs->fs[i].bad_uuid = true;
 			return false;
 		}
 	}
@@ -1283,13 +1285,9 @@ static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path)
 	int err;
 	bool bad_uuid = false;
 
-	/* fsid 0 is reserved for upper fs even with non upper overlay */
-	if (ofs->upper_mnt && ofs->upper_mnt->mnt_sb == sb)
-		return 0;
-
-	for (i = 0; i < ofs->numlowerfs; i++) {
-		if (ofs->lower_fs[i].sb == sb)
-			return i + 1;
+	for (i = 0; i < ofs->numfs; i++) {
+		if (ofs->fs[i].sb == sb)
+			return i;
 	}
 
 	if (!ovl_lower_uuid_ok(ofs, &sb->s_uuid)) {
@@ -1297,7 +1295,7 @@ static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path)
 		if (ofs->config.index || ofs->config.nfs_export) {
 			ofs->config.index = false;
 			ofs->config.nfs_export = false;
-			pr_warn("overlayfs: %s uuid detected in lower fs '%pd2', falling back to index=off,nfs_export=off.\n",
+			pr_warn("%s uuid detected in lower fs '%pd2', falling back to index=off,nfs_export=off.\n",
 				uuid_is_null(&sb->s_uuid) ? "null" :
 							    "conflicting",
 				path->dentry);
@@ -1306,35 +1304,59 @@ static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path)
 
 	err = get_anon_bdev(&dev);
 	if (err) {
-		pr_err("overlayfs: failed to get anonymous bdev for lowerpath\n");
+		pr_err("failed to get anonymous bdev for lowerpath\n");
 		return err;
 	}
 
-	ofs->lower_fs[ofs->numlowerfs].sb = sb;
-	ofs->lower_fs[ofs->numlowerfs].pseudo_dev = dev;
-	ofs->lower_fs[ofs->numlowerfs].bad_uuid = bad_uuid;
-	ofs->numlowerfs++;
+	ofs->fs[ofs->numfs].sb = sb;
+	ofs->fs[ofs->numfs].pseudo_dev = dev;
+	ofs->fs[ofs->numfs].bad_uuid = bad_uuid;
 
-	return ofs->numlowerfs;
+	return ofs->numfs++;
 }
 
-static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs,
-				struct path *stack, unsigned int numlower)
+static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs,
+			  struct path *stack, unsigned int numlower)
 {
 	int err;
 	unsigned int i;
+	struct ovl_layer *layers;
 
 	err = -ENOMEM;
-	ofs->lower_layers = kcalloc(numlower, sizeof(struct ovl_layer),
-				    GFP_KERNEL);
-	if (ofs->lower_layers == NULL)
+	layers = kcalloc(numlower + 1, sizeof(struct ovl_layer), GFP_KERNEL);
+	if (!layers)
 		goto out;
+	ofs->layers = layers;
 
-	ofs->lower_fs = kcalloc(numlower, sizeof(struct ovl_sb),
-				GFP_KERNEL);
-	if (ofs->lower_fs == NULL)
+	ofs->fs = kcalloc(numlower + 1, sizeof(struct ovl_sb), GFP_KERNEL);
+	if (ofs->fs == NULL)
 		goto out;
 
+	/* idx/fsid 0 are reserved for upper fs even with lower only overlay */
+	ofs->numfs++;
+
+	layers[0].mnt = ofs->upper_mnt;
+	layers[0].idx = 0;
+	layers[0].fsid = 0;
+	ofs->numlayer = 1;
+
+	/*
+	 * All lower layers that share the same fs as upper layer, use the same
+	 * pseudo_dev as upper layer.  Allocate fs[0].pseudo_dev even for lower
+	 * only overlay to simplify ovl_fs_free().
+	 * is_lower will be set if upper fs is shared with a lower layer.
+	 */
+	err = get_anon_bdev(&ofs->fs[0].pseudo_dev);
+	if (err) {
+		pr_err("failed to get anonymous bdev for upper fs\n");
+		goto out;
+	}
+
+	if (ofs->upper_mnt) {
+		ofs->fs[0].sb = ofs->upper_mnt->mnt_sb;
+		ofs->fs[0].is_lower = false;
+	}
+
 	for (i = 0; i < numlower; i++) {
 		struct vfsmount *mnt;
 		struct inode *trap;
@@ -1357,7 +1379,7 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs,
 		mnt = clone_private_mount(&stack[i]);
 		err = PTR_ERR(mnt);
 		if (IS_ERR(mnt)) {
-			pr_err("overlayfs: failed to clone lowerpath\n");
+			pr_err("failed to clone lowerpath\n");
 			iput(trap);
 			goto out;
 		}
@@ -1368,15 +1390,13 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs,
 		 */
 		mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME;
 
-		ofs->lower_layers[ofs->numlower].trap = trap;
-		ofs->lower_layers[ofs->numlower].mnt = mnt;
-		ofs->lower_layers[ofs->numlower].idx = i + 1;
-		ofs->lower_layers[ofs->numlower].fsid = fsid;
-		if (fsid) {
-			ofs->lower_layers[ofs->numlower].fs =
-				&ofs->lower_fs[fsid - 1];
-		}
-		ofs->numlower++;
+		layers[ofs->numlayer].trap = trap;
+		layers[ofs->numlayer].mnt = mnt;
+		layers[ofs->numlayer].idx = ofs->numlayer;
+		layers[ofs->numlayer].fsid = fsid;
+		layers[ofs->numlayer].fs = &ofs->fs[fsid];
+		ofs->numlayer++;
+		ofs->fs[fsid].is_lower = true;
 	}
 
 	/*
@@ -1387,22 +1407,23 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs,
 	 * bits reserved for fsid, it emits a warning and uses the original
 	 * inode number.
 	 */
-	if (!ofs->numlowerfs || (ofs->numlowerfs == 1 && !ofs->upper_mnt)) {
-		ofs->xino_bits = 0;
-		ofs->config.xino = OVL_XINO_OFF;
-	} else if (ofs->config.xino == OVL_XINO_ON && !ofs->xino_bits) {
+	if (ofs->numfs - !ofs->upper_mnt == 1) {
+		if (ofs->config.xino == OVL_XINO_ON)
+			pr_info("\"xino=on\" is useless with all layers on same fs, ignore.\n");
+		ofs->xino_mode = 0;
+	} else if (ofs->config.xino == OVL_XINO_ON && ofs->xino_mode < 0) {
 		/*
-		 * This is a roundup of number of bits needed for numlowerfs+1
-		 * (i.e. ilog2(numlowerfs+1 - 1) + 1). fsid 0 is reserved for
-		 * upper fs even with non upper overlay.
+		 * This is a roundup of number of bits needed for encoding
+		 * fsid, where fsid 0 is reserved for upper fs even with
+		 * lower only overlay.
 		 */
 		BUILD_BUG_ON(ilog2(OVL_MAX_STACK) > 31);
-		ofs->xino_bits = ilog2(ofs->numlowerfs) + 1;
+		ofs->xino_mode = ilog2(ofs->numfs - 1) + 1;
 	}
 
-	if (ofs->xino_bits) {
-		pr_info("overlayfs: \"xino\" feature enabled using %d upper inode bits.\n",
-			ofs->xino_bits);
+	if (ofs->xino_mode > 0) {
+		pr_info("\"xino\" feature enabled using %d upper inode bits.\n",
+			ofs->xino_mode);
 	}
 
 	err = 0;
@@ -1428,15 +1449,15 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
 	err = -EINVAL;
 	stacklen = ovl_split_lowerdirs(lowertmp);
 	if (stacklen > OVL_MAX_STACK) {
-		pr_err("overlayfs: too many lower directories, limit is %d\n",
+		pr_err("too many lower directories, limit is %d\n",
 		       OVL_MAX_STACK);
 		goto out_err;
 	} else if (!ofs->config.upperdir && stacklen == 1) {
-		pr_err("overlayfs: at least 2 lowerdir are needed while upperdir nonexistent\n");
+		pr_err("at least 2 lowerdir are needed while upperdir nonexistent\n");
 		goto out_err;
 	} else if (!ofs->config.upperdir && ofs->config.nfs_export &&
 		   ofs->config.redirect_follow) {
-		pr_warn("overlayfs: NFS export requires \"redirect_dir=nofollow\" on non-upper mount, falling back to nfs_export=off.\n");
+		pr_warn("NFS export requires \"redirect_dir=nofollow\" on non-upper mount, falling back to nfs_export=off.\n");
 		ofs->config.nfs_export = false;
 	}
 
@@ -1459,11 +1480,11 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
 	err = -EINVAL;
 	sb->s_stack_depth++;
 	if (sb->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) {
-		pr_err("overlayfs: maximum fs stacking depth exceeded\n");
+		pr_err("maximum fs stacking depth exceeded\n");
 		goto out_err;
 	}
 
-	err = ovl_get_lower_layers(sb, ofs, stack, numlower);
+	err = ovl_get_layers(sb, ofs, stack, numlower);
 	if (err)
 		goto out_err;
 
@@ -1474,7 +1495,7 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
 
 	for (i = 0; i < numlower; i++) {
 		oe->lowerstack[i].dentry = dget(stack[i].dentry);
-		oe->lowerstack[i].layer = &ofs->lower_layers[i];
+		oe->lowerstack[i].layer = &ofs->layers[i+1];
 	}
 
 	if (remote)
@@ -1515,7 +1536,7 @@ static int ovl_check_layer(struct super_block *sb, struct ovl_fs *ofs,
 	while (!err && parent != next) {
 		if (ovl_lookup_trap_inode(sb, parent)) {
 			err = -ELOOP;
-			pr_err("overlayfs: overlapping %s path\n", name);
+			pr_err("overlapping %s path\n", name);
 		} else if (ovl_is_inuse(parent)) {
 			err = ovl_report_in_use(ofs, name);
 		}
@@ -1555,9 +1576,9 @@ static int ovl_check_overlapping_layers(struct super_block *sb,
 			return err;
 	}
 
-	for (i = 0; i < ofs->numlower; i++) {
+	for (i = 1; i < ofs->numlayer; i++) {
 		err = ovl_check_layer(sb, ofs,
-				      ofs->lower_layers[i].mnt->mnt_root,
+				      ofs->layers[i].mnt->mnt_root,
 				      "lowerdir");
 		if (err)
 			return err;
@@ -1595,7 +1616,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 	err = -EINVAL;
 	if (!ofs->config.lowerdir) {
 		if (!silent)
-			pr_err("overlayfs: missing 'lowerdir'\n");
+			pr_err("missing 'lowerdir'\n");
 		goto out_err;
 	}
 
@@ -1603,14 +1624,14 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_maxbytes = MAX_LFS_FILESIZE;
 	/* Assume underlaying fs uses 32bit inodes unless proven otherwise */
 	if (ofs->config.xino != OVL_XINO_OFF)
-		ofs->xino_bits = BITS_PER_LONG - 32;
+		ofs->xino_mode = BITS_PER_LONG - 32;
 
 	/* alloc/destroy_inode needed for setting up traps in inode cache */
 	sb->s_op = &ovl_super_operations;
 
 	if (ofs->config.upperdir) {
 		if (!ofs->config.workdir) {
-			pr_err("overlayfs: missing 'workdir'\n");
+			pr_err("missing 'workdir'\n");
 			goto out_err;
 		}
 
@@ -1660,13 +1681,13 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 	if (!ofs->indexdir) {
 		ofs->config.index = false;
 		if (ofs->upper_mnt && ofs->config.nfs_export) {
-			pr_warn("overlayfs: NFS export requires an index dir, falling back to nfs_export=off.\n");
+			pr_warn("NFS export requires an index dir, falling back to nfs_export=off.\n");
 			ofs->config.nfs_export = false;
 		}
 	}
 
 	if (ofs->config.metacopy && ofs->config.nfs_export) {
-		pr_warn("overlayfs: NFS export is not supported with metadata only copy up, falling back to nfs_export=off.\n");
+		pr_warn("NFS export is not supported with metadata only copy up, falling back to nfs_export=off.\n");
 		ofs->config.nfs_export = false;
 	}
 
@@ -1749,9 +1770,15 @@ static int __init ovl_init(void)
 	if (ovl_inode_cachep == NULL)
 		return -ENOMEM;
 
-	err = register_filesystem(&ovl_fs_type);
-	if (err)
-		kmem_cache_destroy(ovl_inode_cachep);
+	err = ovl_aio_request_cache_init();
+	if (!err) {
+		err = register_filesystem(&ovl_fs_type);
+		if (!err)
+			return 0;
+
+		ovl_aio_request_cache_destroy();
+	}
+	kmem_cache_destroy(ovl_inode_cachep);
 
 	return err;
 }
@@ -1766,7 +1793,7 @@ static void __exit ovl_exit(void)
 	 */
 	rcu_barrier();
 	kmem_cache_destroy(ovl_inode_cachep);
-
+	ovl_aio_request_cache_destroy();
 }
 
 module_init(ovl_init);