[RFC v2 13/83] Add remount_fs and show_options methods.

Andiry Xu
2018-03-10T18:20:37Z

fs/nova/super.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)

diff --git a/fs/nova/super.c b/fs/nova/super.c
index 3efb560..f41cc04 100644
--- a/fs/nova/super.c
+++ b/fs/nova/super.c
@@ -617,6 +617,59 @@ static int nova_fill_super(struct super_block *sb, void *data, int silent)
return retval;
}

+static int nova_show_options(struct seq_file *seq, struct dentry *root)
+{
+ struct nova_sb_info *sbi = NOVA_SB(root->d_sb);
+
+ if (sbi->mode != (0777 | S_ISVTX))
+ seq_printf(seq, ",mode=%03o", sbi->mode);
+ if (uid_valid(sbi->uid))
+ seq_printf(seq, ",uid=%u", from_kuid(&init_user_ns, sbi->uid));
+ if (gid_valid(sbi->gid))
+ seq_printf(seq, ",gid=%u", from_kgid(&init_user_ns, sbi->gid));
+ if (test_opt(root->d_sb, ERRORS_RO))
+ seq_puts(seq, ",errors=remount-ro");
+ if (test_opt(root->d_sb, ERRORS_PANIC))
+ seq_puts(seq, ",errors=panic");
+ if (test_opt(root->d_sb, DAX))
+ seq_puts(seq, ",dax");
+
+ return 0;
+}
+
+static int nova_remount(struct super_block *sb, int *mntflags, char *data)
+{
+ unsigned long old_sb_flags;
+ unsigned long old_mount_opt;
+ struct nova_sb_info *sbi = NOVA_SB(sb);
+ int ret = -EINVAL;
+
+ /* Store the old options */
+ mutex_lock(&sbi->s_lock);
+ old_sb_flags = sb->s_flags;
+ old_mount_opt = sbi->s_mount_opt;
+
+ if (nova_parse_options(data, sbi, 1))
+ goto restore_opt;
+
+ sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+ ((sbi->s_mount_opt & NOVA_MOUNT_POSIX_ACL) ?
+ MS_POSIXACL : 0);
+
+ if ((*mntflags & MS_RDONLY) != (sb->s_flags & MS_RDONLY))
+ nova_update_mount_time(sb);
+
+ mutex_unlock(&sbi->s_lock);
+ ret = 0;
+ return ret;
+
+restore_opt:
+ sb->s_flags = old_sb_flags;
+ sbi->s_mount_opt = old_mount_opt;
+ mutex_unlock(&sbi->s_lock);
+ return ret;
+}
+
static void nova_put_super(struct super_block *sb)
{
struct nova_sb_info *sbi = NOVA_SB(sb);
@@ -697,6 +750,8 @@ static struct super_operations nova_sops = {
.alloc_inode = nova_alloc_inode,
.destroy_inode = nova_destroy_inode,
.put_super = nova_put_super,
+ .remount_fs = nova_remount,
+ .show_options = nova_show_options,
};

static struct dentry *nova_mount(struct file_system_type *fs_type,
--
2.7.4