aufs: dirren 6/6, mount options

Introduce the new mount options, dirren and nodirren, which activates
and deactivates DIRREN feature.
In remount and unmount, the inum-list per branch should be flushed to
the file.
Signed-off-by: J. R. Okajima <hooanon05g@gmail.com>

fs/aufs/dirren.c

@@ -1243,3 +1243,61 @@ int au_dr_lkup_h_ino(struct au_do_lookup_args *lkup, aufs_bindex_t bindex,
 out:
 	return match;
 }
+
+/* ---------------------------------------------------------------------- */
+
+int au_dr_opt_set(struct super_block *sb)
+{
+	int err;
+	aufs_bindex_t bindex, bbot;
+	struct au_branch *br;
+
+	err = 0;
+	bbot = au_sbbot(sb);
+	for (bindex = 0; !err && bindex <= bbot; bindex++) {
+		br = au_sbr(sb, bindex);
+		err = au_dr_hino(sb, bindex, /*br*/NULL, &br->br_path);
+	}
+
+	return err;
+}
+
+int au_dr_opt_flush(struct super_block *sb)
+{
+	int err;
+	aufs_bindex_t bindex, bbot;
+	struct au_branch *br;
+
+	err = 0;
+	bbot = au_sbbot(sb);
+	for (bindex = 0; !err && bindex <= bbot; bindex++) {
+		br = au_sbr(sb, bindex);
+		if (au_br_writable(br->br_perm))
+			err = au_dr_hino(sb, bindex, /*br*/NULL, /*path*/NULL);
+	}
+
+	return err;
+}
+
+int au_dr_opt_clr(struct super_block *sb, int no_flush)
+{
+	int err;
+	aufs_bindex_t bindex, bbot;
+	struct au_branch *br;
+
+	err = 0;
+	if (!no_flush) {
+		err = au_dr_opt_flush(sb);
+		if (unlikely(err))
+			goto out;
+	}
+
+	bbot = au_sbbot(sb);
+	for (bindex = 0; bindex <= bbot; bindex++) {
+		br = au_sbr(sb, bindex);
+		au_dr_hino_free(&br->br_dirren);
+	}
+
+out:
+	return err;
+}

fs/aufs/dirren.h

@@ -86,6 +86,9 @@ int au_dr_lkup_name(struct au_do_lookup_args *lkup, aufs_bindex_t btgt);
 int au_dr_lkup_h_ino(struct au_do_lookup_args *lkup, aufs_bindex_t bindex,
 		     ino_t h_ino);
 void au_dr_lkup_fin(struct au_do_lookup_args *lkup);
+int au_dr_opt_set(struct super_block *sb);
+int au_dr_opt_flush(struct super_block *sb);
+int au_dr_opt_clr(struct super_block *sb, int no_flush);
 #else
 AuStubInt0(au_dr_hino_test_add, struct au_dr_br *dr, ino_t h_ino,
 	   struct au_dr_hino *add_ent);
@@ -104,6 +107,9 @@ AuStubInt0(au_dr_lkup_name, struct au_do_lookup_args *lkup, aufs_bindex_t btgt);
 AuStubInt0(au_dr_lkup_h_ino, struct au_do_lookup_args *lkup,
 	   aufs_bindex_t bindex, ino_t h_ino);
 AuStubVoid(au_dr_lkup_fin, struct au_do_lookup_args *lkup);
+AuStubInt0(au_dr_opt_set, struct super_block *sb);
+AuStubInt0(au_dr_opt_flush, struct super_block *sb);
+AuStubInt0(au_dr_opt_clr, struct super_block *sb, int no_flush);
 #endif
 
 /* ---------------------------------------------------------------------- */

fs/aufs/opts.c

@@ -31,6 +31,7 @@ enum {
 	Opt_verbose, Opt_noverbose,
 	Opt_sum, Opt_nosum, Opt_wsum,
 	Opt_dirperm1, Opt_nodirperm1,
+	Opt_dirren, Opt_nodirren,
 	Opt_acl, Opt_noacl,
 	Opt_tail, Opt_ignore, Opt_ignore_silent, Opt_err
 };
@@ -85,6 +86,14 @@ static match_table_t options = {
 	{Opt_dio, "dio"},
 	{Opt_nodio, "nodio"},
 
+#ifdef CONFIG_AUFS_DIRREN
+	{Opt_dirren, "dirren"},
+	{Opt_nodirren, "nodirren"},
+#else
+	{Opt_ignore, "dirren"},
+	{Opt_ignore_silent, "nodirren"},
+#endif
+
 	{Opt_dirperm1, "dirperm1"},
 	{Opt_nodirperm1, "nodirperm1"},
 
@@ -634,6 +643,12 @@ static void dump_opts(struct au_opts *opts)
 			AuDbg("copyup %d, %s\n", opt->wbr_copyup,
 				  au_optstr_wbr_copyup(opt->wbr_copyup));
 			break;
+		case Opt_dirren:
+			AuLabel(dirren);
+			break;
+		case Opt_nodirren:
+			AuLabel(nodirren);
+			break;
 		case Opt_acl:
 			AuLabel(acl);
 			break;
@@ -1078,6 +1093,8 @@ int au_opts_parse(struct super_block *sb, char *str, struct au_opts *opts)
 		case Opt_wsum:
 		case Opt_rdblk_def:
 		case Opt_rdhash_def:
+		case Opt_dirren:
+		case Opt_nodirren:
 		case Opt_acl:
 		case Opt_noacl:
 			err = 0;
@@ -1306,6 +1323,28 @@ static int au_opt_simple(struct super_block *sb, struct au_opt *opt,
 		au_fclr_opts(opts->flags, TRUNC_XIB);
 		break;
 
+	case Opt_dirren:
+		err = 1;
+		if (!au_opt_test(sbinfo->si_mntflags, DIRREN)) {
+			err = au_dr_opt_set(sb);
+			if (!err)
+				err = 1;
+		}
+		if (err == 1)
+			au_opt_set(sbinfo->si_mntflags, DIRREN);
+		break;
+	case Opt_nodirren:
+		err = 1;
+		if (au_opt_test(sbinfo->si_mntflags, DIRREN)) {
+			err = au_dr_opt_clr(sb, au_ftest_opts(opts->flags,
+							      DR_FLUSHED));
+			if (!err)
+				err = 1;
+		}
+		if (err == 1)
+			au_opt_clr(sbinfo->si_mntflags, DIRREN);
+		break;
+
 	case Opt_acl:
 		sb->s_flags |= SB_POSIXACL;
 		break;
@@ -1625,7 +1664,11 @@ int au_opts_remount(struct super_block *sb, struct au_opts *opts)
 
 	SiMustWriteLock(sb);
 
-	err = 0;
+	err = au_dr_opt_flush(sb);
+	if (unlikely(err))
+		goto out;
+	au_fset_opts(opts->flags, DR_FLUSHED);
+
 	dir = d_inode(sb->s_root);
 	sbinfo = au_sbi(sb);
 	opt_xino = NULL;
@@ -1667,6 +1710,7 @@ int au_opts_remount(struct super_block *sb, struct au_opts *opts)
 
 	AuDbg("status 0x%x\n", opts->flags);
 
+out:
 	return err;
 }
 

fs/aufs/opts.h

@@ -162,12 +162,18 @@ struct au_opt {
 #define AuOpts_TRUNC_XIB	(1 << 2)
 #define AuOpts_REFRESH_DYAOP	(1 << 3)
 #define AuOpts_REFRESH_IDOP	(1 << 4)
+#define AuOpts_DR_FLUSHED	(1 << 5)
 #define au_ftest_opts(flags, name)	((flags) & AuOpts_##name)
 #define au_fset_opts(flags, name) \
 	do { (flags) |= AuOpts_##name; } while (0)
 #define au_fclr_opts(flags, name) \
 	do { (flags) &= ~AuOpts_##name; } while (0)
 
+#ifndef CONFIG_AUFS_DIRREN
+#undef AuOpts_DR_FLUSHED
+#define AuOpts_DR_FLUSHED	0
+#endif
+
 struct au_opts {
 	struct au_opt	*opt;
 	int		max_opt;

fs/aufs/super.c

@@ -276,6 +276,7 @@ static int aufs_show_options(struct seq_file *m, struct dentry *dentry)
 	AuUInt(RDBLK, rdblk, sbinfo->si_rdblk);
 	AuUInt(RDHASH, rdhash, sbinfo->si_rdhash);
 
+	AuBool(DIRREN, dirren);
 	AuBool(SUM, sum);
 	/* AuBool(SUM_W, wsum); */
 	AuBool(VERBOSE, verbose);
@@ -1006,6 +1007,7 @@ static void aufs_kill_sb(struct super_block *sb)
 		if (au_opt_test(sbinfo->si_mntflags, PLINK))
 			au_plink_put(sb, /*verbose*/1);
 		au_xino_clr(sb);
+		au_dr_opt_flush(sb);
 		sbinfo->si_sb = NULL;
 		aufs_write_unlock(sb->s_root);
 		au_nwt_flush(&sbinfo->si_nowait);