ovl: remove redundant ofs->indexdir member

When the index feature is disabled, ofs->indexdir is NULL.
When the index feature is enabled, ofs->indexdir has the same value as
ofs->workdir and takes an extra reference.

This makes the code harder to understand when it is not always clear
that ofs->indexdir in one function is the same dentry as ofs->workdir
in another function.

Remove this redundancy, by referencing ofs->workdir directly in index
helpers and by using the ovl_indexdir() accessor in generic code.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>

1 files changed, 8 insertions, 11 deletions

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index a0967bb25003..f78161cf8388 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -853,10 +853,8 @@ 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;
@@ -869,16 +867,15 @@ 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_origin_xattr(ofs, ofs->indexdir,
+		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");
 
@@ -886,7 +883,7 @@ 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:
@@ -1406,7 +1403,7 @@ 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;
 	}
 
@@ -1415,7 +1412,7 @@ 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");