[PATCH] zonefs: add uid,gid,perm mount option

[tomwei7g@xxxxxxxxx]

From: cheng wei <tomwei7g@xxxxxxxxx>

Zonefs has no way to easily modify file permissions.
though we can run mkzonefs again to reset file permissions but it
also change uuid that case a lot of problam.

To solve this problem add permissions mount option may a good way,
we can specify permissions when mount and without zonefs userland tools.

Signed-off-by: cheng wei <tomwei7g@xxxxxxxxx>
---
 fs/zonefs/super.c  | 42 ++++++++++++++++++++++++++++++++++++++++--
 fs/zonefs/zonefs.h |  3 +++
 2 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
index 0fe76f376dee..188a2e7bdda7 100644
--- a/fs/zonefs/super.c
+++ b/fs/zonefs/super.c
@@ -1136,7 +1136,7 @@ static int zonefs_statfs(struct dentry *dentry, struct kstatfs *buf)
 
 enum {
 	Opt_errors_ro, Opt_errors_zro, Opt_errors_zol, Opt_errors_repair,
-	Opt_explicit_open, Opt_err,
+	Opt_explicit_open, Opt_uid, Opt_gid, Opt_perm, Opt_err,
 };
 
 static const match_table_t tokens = {
@@ -1145,7 +1145,10 @@ static const match_table_t tokens = {
 	{ Opt_errors_zol,	"errors=zone-offline"},
 	{ Opt_errors_repair,	"errors=repair"},
 	{ Opt_explicit_open,	"explicit-open" },
-	{ Opt_err,		NULL}
+	{ Opt_uid,	"uid=%d" },
+	{ Opt_gid,	"gid=%d" },
+	{ Opt_perm,	"perm=%d" },
+	{ Opt_err,	NULL}
 };
 
 static int zonefs_parse_options(struct super_block *sb, char *options)
@@ -1159,10 +1162,13 @@ static int zonefs_parse_options(struct super_block *sb, char *options)
 
 	while ((p = strsep(&options, ",")) != NULL) {
 		int token;
+		int arg;
 
 		if (!*p)
 			continue;
 
+		args[0].to = args[0].from = NULL;
+
 		token = match_token(p, tokens, args);
 		switch (token) {
 		case Opt_errors_ro:
@@ -1184,6 +1190,32 @@ static int zonefs_parse_options(struct super_block *sb, char *options)
 		case Opt_explicit_open:
 			sbi->s_mount_opts |= ZONEFS_MNTOPT_EXPLICIT_OPEN;
 			break;
+		case Opt_uid:
+			sbi->s_mount_opts |= ZONEFS_MNTOPT_UID;
+			if(args->from && match_int(args, &arg))
+				return -EINVAL;
+			sbi->s_uid = make_kuid(current_user_ns(), arg);
+			if (!uid_valid(sbi->s_uid)) {
+				zonefs_err(sb, "Invalid uid value %d\n", arg);
+				return -EINVAL;
+			}
+			break;
+		case Opt_gid:
+			sbi->s_mount_opts |= ZONEFS_MNTOPT_GID;
+			if(args->from && match_int(args, &arg))
+				return -EINVAL;
+			sbi->s_gid = make_kgid(current_user_ns(), arg);
+			if (!gid_valid(sbi->s_gid)) {
+				zonefs_err(sb, "Invalid gid value %d\n", arg);
+				return -EINVAL;
+			}
+			break;
+		case Opt_perm:
+			sbi->s_mount_opts |= ZONEFS_MNTOPT_PERM;
+			if(args->from && match_int(args, &arg))
+				return -EINVAL;
+			sbi->s_perm = arg;
+			break;
 		default:
 			return -EINVAL;
 		}
@@ -1204,6 +1236,12 @@ static int zonefs_show_options(struct seq_file *seq, struct dentry *root)
 		seq_puts(seq, ",errors=zone-offline");
 	if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_REPAIR)
 		seq_puts(seq, ",errors=repair");
+	if (sbi->s_mount_opts & ZONEFS_MNTOPT_UID)
+		seq_printf(seq, ",uid=%u", from_kuid(&init_user_ns, sbi->s_uid));
+	if (sbi->s_mount_opts & ZONEFS_MNTOPT_GID)
+		seq_printf(seq, ",gid=%u", from_kgid(&init_user_ns, sbi->s_gid));
+	if (sbi->s_mount_opts & ZONEFS_MNTOPT_PERM)
+		seq_printf(seq, ",perm=0%o", sbi->s_perm);
 
 	return 0;
 }
diff --git a/fs/zonefs/zonefs.h b/fs/zonefs/zonefs.h
index 51141907097c..234b203b7436 100644
--- a/fs/zonefs/zonefs.h
+++ b/fs/zonefs/zonefs.h
@@ -161,6 +161,9 @@ enum zonefs_features {
 	(ZONEFS_MNTOPT_ERRORS_RO | ZONEFS_MNTOPT_ERRORS_ZRO | \
 	 ZONEFS_MNTOPT_ERRORS_ZOL | ZONEFS_MNTOPT_ERRORS_REPAIR)
 #define ZONEFS_MNTOPT_EXPLICIT_OPEN	(1 << 4) /* Explicit open/close of zones on open/close */
+#define ZONEFS_MNTOPT_UID	(1 << 5) /* Specify file uid */
+#define ZONEFS_MNTOPT_GID	(1 << 6) /* Specify file gid */
+#define ZONEFS_MNTOPT_PERM	(1 << 7) /* Specify file perm */
 
 /*
  * In-memory Super block information.

base-commit: 1e28eed17697bcf343c6743f0028cc3b5dd88bf0
-- 
2.31.1