1 files changed, 73 insertions, 123 deletions

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 17864a8d2b85..06a231970cb5 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -28,41 +28,38 @@ MODULE_LICENSE("GPL");
 
 struct ovl_dir_cache;
 
-static struct dentry *ovl_d_real(struct dentry *dentry,
-				 const struct inode *inode)
+static struct dentry *ovl_d_real(struct dentry *dentry, enum d_real_type type)
 {
-	struct dentry *real = NULL, *lower;
+	struct dentry *upper, *lower;
 	int err;
 
-	/*
-	 * vfs is only expected to call d_real() with NULL from d_real_inode()
-	 * and with overlay inode from file_dentry() on an overlay file.
-	 *
-	 * TODO: remove @inode argument from d_real() API, remove code in this
-	 * function that deals with non-NULL @inode and remove d_real() call
-	 * from file_dentry().
-	 */
-	if (inode && d_inode(dentry) == inode)
-		return dentry;
-	else if (inode)
+	switch (type) {
+	case D_REAL_DATA:
+	case D_REAL_METADATA:
+		break;
+	default:
 		goto bug;
+	}
 
 	if (!d_is_reg(dentry)) {
 		/* d_real_inode() is only relevant for regular files */
 		return dentry;
 	}
 
-	real = ovl_dentry_upper(dentry);
-	if (real && (inode == d_inode(real)))
-		return real;
+	upper = ovl_dentry_upper(dentry);
+	if (upper && (type == D_REAL_METADATA ||
+		      ovl_has_upperdata(d_inode(dentry))))
+		return upper;
 
-	if (real && !inode && ovl_has_upperdata(d_inode(dentry)))
-		return real;
+	if (type == D_REAL_METADATA) {
+		lower = ovl_dentry_lower(dentry);
+		goto real_lower;
+	}
 
 	/*
-	 * Best effort lazy lookup of lowerdata for !inode case to return
+	 * Best effort lazy lookup of lowerdata for D_REAL_DATA case to return
 	 * the real lowerdata dentry.  The only current caller of d_real() with
-	 * NULL inode is d_real_inode() from trace_uprobe and this caller is
+	 * D_REAL_DATA is d_real_inode() from trace_uprobe and this caller is
 	 * likely going to be followed reading from the file, before placing
 	 * uprobes on offset within the file, so lowerdata should be available
 	 * when setting the uprobe.
@@ -73,18 +70,13 @@ static struct dentry *ovl_d_real(struct dentry *dentry,
 	lower = ovl_dentry_lowerdata(dentry);
 	if (!lower)
 		goto bug;
-	real = lower;
 
-	/* Handle recursion */
-	real = d_real(real, inode);
+real_lower:
+	/* Handle recursion into stacked lower fs */
+	return d_real(lower, type);
 
-	if (!inode || inode == d_inode(real))
-		return real;
 bug:
-	WARN(1, "%s(%pd4, %s:%lu): real dentry (%p/%lu) not found\n",
-	     __func__, dentry, inode ? inode->i_sb->s_id : "NULL",
-	     inode ? inode->i_ino : 0, real,
-	     real && d_inode(real) ? d_inode(real)->i_ino : 0);
+	WARN(1, "%s(%pd4, %d): real dentry not found\n", __func__, dentry, type);
 	return dentry;
 }
 
@@ -439,74 +431,14 @@ static bool ovl_workdir_ok(struct dentry *workdir, struct dentry *upperdir)
 	bool ok = false;
 
 	if (workdir != upperdir) {
-		ok = (lock_rename(workdir, upperdir) == NULL);
-		unlock_rename(workdir, upperdir);
+		struct dentry *trap = lock_rename(workdir, upperdir);
+		if (!IS_ERR(trap))
+			unlock_rename(workdir, upperdir);
+		ok = (trap == NULL);
 	}
 	return ok;
 }
 
-static int ovl_own_xattr_get(const struct xattr_handler *handler,
-			     struct dentry *dentry, struct inode *inode,
-			     const char *name, void *buffer, size_t size)
-{
-	return -EOPNOTSUPP;
-}
-
-static int ovl_own_xattr_set(const struct xattr_handler *handler,
-			     struct mnt_idmap *idmap,
-			     struct dentry *dentry, struct inode *inode,
-			     const char *name, const void *value,
-			     size_t size, int flags)
-{
-	return -EOPNOTSUPP;
-}
-
-static int ovl_other_xattr_get(const struct xattr_handler *handler,
-			       struct dentry *dentry, struct inode *inode,
-			       const char *name, void *buffer, size_t size)
-{
-	return ovl_xattr_get(dentry, inode, name, buffer, size);
-}
-
-static int ovl_other_xattr_set(const struct xattr_handler *handler,
-			       struct mnt_idmap *idmap,
-			       struct dentry *dentry, struct inode *inode,
-			       const char *name, const void *value,
-			       size_t size, int flags)
-{
-	return ovl_xattr_set(dentry, inode, name, value, size, flags);
-}
-
-static const struct xattr_handler ovl_own_trusted_xattr_handler = {
-	.prefix	= OVL_XATTR_TRUSTED_PREFIX,
-	.get = ovl_own_xattr_get,
-	.set = ovl_own_xattr_set,
-};
-
-static const struct xattr_handler ovl_own_user_xattr_handler = {
-	.prefix	= OVL_XATTR_USER_PREFIX,
-	.get = ovl_own_xattr_get,
-	.set = ovl_own_xattr_set,
-};
-
-static const struct xattr_handler ovl_other_xattr_handler = {
-	.prefix	= "", /* catch all */
-	.get = ovl_other_xattr_get,
-	.set = ovl_other_xattr_set,
-};
-
-static const struct xattr_handler * const ovl_trusted_xattr_handlers[] = {
-	&ovl_own_trusted_xattr_handler,
-	&ovl_other_xattr_handler,
-	NULL
-};
-
-static const struct xattr_handler * const ovl_user_xattr_handlers[] = {
-	&ovl_own_user_xattr_handler,
-	&ovl_other_xattr_handler,
-	NULL
-};
-
 static int ovl_setup_trap(struct super_block *sb, struct dentry *dir,
 			  struct inode **ptrap, const char *name)
 {
@@ -647,7 +579,7 @@ static int ovl_check_rename_whiteout(struct ovl_fs *ofs)
 	if (IS_ERR(whiteout))
 		goto cleanup_temp;
 
-	err = ovl_is_whiteout(whiteout);
+	err = ovl_upper_is_whiteout(ofs, whiteout);
 
 	/* Best effort cleanup of whiteout and temp file */
 	if (err)
@@ -887,15 +819,20 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs,
 {
 	struct vfsmount *mnt = ovl_upper_mnt(ofs);
 	struct dentry *indexdir;
+	struct dentry *origin = ovl_lowerstack(oe)->dentry;
+	const struct ovl_fh *fh;
 	int err;
 
+	fh = ovl_get_origin_fh(ofs, origin);
+	if (IS_ERR(fh))
+		return PTR_ERR(fh);
+
 	err = mnt_want_write(mnt);
 	if (err)
-		return err;
+		goto out_free_fh;
 
 	/* Verify lower root is upper root origin */
-	err = ovl_verify_origin(ofs, upperpath->dentry,
-				ovl_lowerstack(oe)->dentry, true);
+	err = ovl_verify_origin_fh(ofs, upperpath->dentry, fh, true);
 	if (err) {
 		pr_err("failed to verify upper root origin\n");
 		goto out;
@@ -910,10 +847,8 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs,
 	if (IS_ERR(indexdir)) {
 		err = PTR_ERR(indexdir);
 	} else if (indexdir) {
-		ofs->indexdir = indexdir;
-		ofs->workdir = dget(indexdir);
-
-		err = ovl_setup_trap(sb, ofs->indexdir, &ofs->indexdir_trap,
+		ofs->workdir = indexdir;
+		err = ovl_setup_trap(sb, indexdir, &ofs->workdir_trap,
 				     "indexdir");
 		if (err)
 			goto out;
@@ -926,15 +861,15 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs,
 		 * ".overlay.upper" to indicate that index may have
 		 * directory entries.
 		 */
-		if (ovl_check_origin_xattr(ofs, ofs->indexdir)) {
-			err = ovl_verify_set_fh(ofs, ofs->indexdir,
-						OVL_XATTR_ORIGIN,
-						upperpath->dentry, true, false);
+		if (ovl_check_origin_xattr(ofs, indexdir)) {
+			err = ovl_verify_origin_xattr(ofs, indexdir,
+						      OVL_XATTR_ORIGIN,
+						      upperpath->dentry, true,
+						      false);
 			if (err)
 				pr_err("failed to verify index dir 'origin' xattr\n");
 		}
-		err = ovl_verify_upper(ofs, ofs->indexdir, upperpath->dentry,
-				       true);
+		err = ovl_verify_upper(ofs, indexdir, upperpath->dentry, true);
 		if (err)
 			pr_err("failed to verify index dir 'upper' xattr\n");
 
@@ -942,11 +877,13 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs,
 		if (!err)
 			err = ovl_indexdir_cleanup(ofs);
 	}
-	if (err || !ofs->indexdir)
+	if (err || !indexdir)
 		pr_warn("try deleting index dir or mounting with '-o index=off' to disable inodes index.\n");
 
 out:
 	mnt_drop_write(mnt);
+out_free_fh:
+	kfree(fh);
 	return err;
 }
 
@@ -1304,6 +1241,7 @@ static struct dentry *ovl_get_root(struct super_block *sb,
 				   struct ovl_entry *oe)
 {
 	struct dentry *root;
+	struct ovl_fs *ofs = OVL_FS(sb);
 	struct ovl_path *lowerpath = ovl_lowerstack(oe);
 	unsigned long ino = d_inode(lowerpath->dentry)->i_ino;
 	int fsid = lowerpath->layer->fsid;
@@ -1325,6 +1263,20 @@ static struct dentry *ovl_get_root(struct super_block *sb,
 			ovl_set_flag(OVL_IMPURE, d_inode(root));
 	}
 
+	/* Look for xwhiteouts marker except in the lowermost layer */
+	for (int i = 0; i < ovl_numlower(oe) - 1; i++, lowerpath++) {
+		struct path path = {
+			.mnt = lowerpath->layer->mnt,
+			.dentry = lowerpath->dentry,
+		};
+
+		/* overlay.opaque=x means xwhiteouts directory */
+		if (ovl_get_opaquedir_val(ofs, &path) == 'x') {
+			ovl_layer_set_xwhiteouts(ofs, lowerpath->layer);
+			ovl_dentry_set_xwhiteouts(root);
+		}
+	}
+
 	/* Root is always merge -> can have whiteouts */
 	ovl_set_flag(OVL_WHITEOUTS, d_inode(root));
 	ovl_dentry_set_flag(OVL_E_CONNECTED, root);
@@ -1382,8 +1334,11 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
 	ofs->layers = layers;
 	/*
 	 * Layer 0 is reserved for upper even if there's no upper.
-	 * For consistency, config.lowerdirs[0] is NULL.
+	 * config.lowerdirs[0] is used for storing the user provided colon
+	 * separated lowerdir string.
 	 */
+	ofs->config.lowerdirs[0] = ctx->lowerdir_all;
+	ctx->lowerdir_all = NULL;
 	ofs->numlayer = 1;
 
 	sb->s_stack_depth = 0;
@@ -1457,7 +1412,7 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
 			goto out_free_oe;
 
 		/* Force r/o mount with no index dir */
-		if (!ofs->indexdir)
+		if (!ofs->workdir)
 			sb->s_flags |= SB_RDONLY;
 	}
 
@@ -1466,7 +1421,7 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
 		goto out_free_oe;
 
 	/* Show index=off in /proc/mounts for forced r/o mount */
-	if (!ofs->indexdir) {
+	if (!ofs->workdir) {
 		ofs->config.index = false;
 		if (ovl_upper_mnt(ofs) && ofs->config.nfs_export) {
 			pr_warn("NFS export requires an index dir, falling back to nfs_export=off.\n");
@@ -1493,8 +1448,7 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
 	cap_lower(cred->cap_effective, CAP_SYS_RESOURCE);
 
 	sb->s_magic = OVERLAYFS_SUPER_MAGIC;
-	sb->s_xattr = ofs->config.userxattr ? ovl_user_xattr_handlers :
-		ovl_trusted_xattr_handlers;
+	sb->s_xattr = ovl_xattr_handlers(ofs);
 	sb->s_fs_info = ofs;
 #ifdef CONFIG_FS_POSIX_ACL
 	sb->s_flags |= SB_POSIXACL;
@@ -1506,6 +1460,7 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
 	 * lead to unexpected results.
 	 */
 	sb->s_iflags |= SB_I_NOUMASK;
+	sb->s_iflags |= SB_I_EVM_HMAC_UNSUPPORTED;
 
 	err = -ENOMEM;
 	root_dentry = ovl_get_root(sb, ctx->upper.dentry, oe);
@@ -1548,19 +1503,15 @@ static int __init ovl_init(void)
 	ovl_inode_cachep = kmem_cache_create("ovl_inode",
 					     sizeof(struct ovl_inode), 0,
 					     (SLAB_RECLAIM_ACCOUNT|
-					      SLAB_MEM_SPREAD|SLAB_ACCOUNT),
+					      SLAB_ACCOUNT),
 					     ovl_inode_init_once);
 	if (ovl_inode_cachep == NULL)
 		return -ENOMEM;
 
-	err = ovl_aio_request_cache_init();
-	if (!err) {
-		err = register_filesystem(&ovl_fs_type);
-		if (!err)
-			return 0;
+	err = register_filesystem(&ovl_fs_type);
+	if (!err)
+		return 0;
 
-		ovl_aio_request_cache_destroy();
-	}
 	kmem_cache_destroy(ovl_inode_cachep);
 
 	return err;
@@ -1576,7 +1527,6 @@ static void __exit ovl_exit(void)
 	 */
 	rcu_barrier();
 	kmem_cache_destroy(ovl_inode_cachep);
-	ovl_aio_request_cache_destroy();
 }
 
 module_init(ovl_init);