[PATCH 09/14] affs: Implement show_options

From: David Howells
Date: Wed Jul 05 2017 - 11:25:29 EST


Implement the show_options superblock op for affs as part of a bid to get
rid of s_options and generic_show_options() to make it easier to implement
a context-based mount where the mount options can be passed individually
over a file descriptor.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

fs/affs/super.c | 42 +++++++++++++++++++++++++++++++++++++-----
1 file changed, 37 insertions(+), 5 deletions(-)

diff --git a/fs/affs/super.c b/fs/affs/super.c
index c2c27a8f128e..7bf47a41cb4f 100644
--- a/fs/affs/super.c
+++ b/fs/affs/super.c
@@ -20,9 +20,11 @@
#include <linux/slab.h>
#include <linux/writeback.h>
#include <linux/blkdev.h>
+#include <linux/seq_file.h>
#include "affs.h"

static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
+static int affs_show_options(struct seq_file *m, struct dentry *root);
static int affs_remount (struct super_block *sb, int *flags, char *data);

static void
@@ -159,7 +161,7 @@ static const struct super_operations affs_sops = {
.sync_fs = affs_sync_fs,
.statfs = affs_statfs,
.remount_fs = affs_remount,
- .show_options = generic_show_options,
+ .show_options = affs_show_options,
};

enum {
@@ -293,6 +295,40 @@ parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved,
return 1;
}

+static int affs_show_options(struct seq_file *m, struct dentry *root)
+{
+ struct super_block *sb = root->d_sb;
+ struct affs_sb_info *sbi = AFFS_SB(sb);
+
+ if (sb->s_blocksize)
+ seq_printf(m, ",bs=%lu", sb->s_blocksize);
+ if (affs_test_opt(sbi->s_flags, SF_SETMODE))
+ seq_printf(m, ",mode=%o", sbi->s_mode);
+ if (affs_test_opt(sbi->s_flags, SF_MUFS))
+ seq_puts(m, ",mufs");
+ if (affs_test_opt(sbi->s_flags, SF_NO_TRUNCATE))
+ seq_puts(m, ",nofilenametruncate");
+ if (affs_test_opt(sbi->s_flags, SF_PREFIX))
+ seq_printf(m, ",prefix=%s", sbi->s_prefix);
+ if (affs_test_opt(sbi->s_flags, SF_IMMUTABLE))
+ seq_puts(m, ",protect");
+ if (sbi->s_reserved != 2)
+ seq_printf(m, ",reserved=%u", sbi->s_reserved);
+ if (sbi->s_root_block != (sbi->s_reserved + sbi->s_partition_size - 1) / 2)
+ seq_printf(m, ",root=%u", sbi->s_root_block);
+ if (affs_test_opt(sbi->s_flags, SF_SETGID))
+ seq_printf(m, ",setgid=%u",
+ from_kgid_munged(&init_user_ns, sbi->s_gid));
+ if (affs_test_opt(sbi->s_flags, SF_SETUID))
+ seq_printf(m, ",setuid=%u",
+ from_kuid_munged(&init_user_ns, sbi->s_uid));
+ if (affs_test_opt(sbi->s_flags, SF_VERBOSE))
+ seq_puts(m, ",verbose");
+ if (sbi->s_volume[0])
+ seq_printf(m, ",volume=%s", sbi->s_volume);
+ return 0;
+}
+
/* This function definitely needs to be split up. Some fine day I'll
* hopefully have the guts to do so. Until then: sorry for the mess.
*/
@@ -316,8 +352,6 @@ static int affs_fill_super(struct super_block *sb, void *data, int silent)
u8 sig[4];
int ret;

- save_mount_options(sb, data);
-
pr_debug("read_super(%s)\n", data ? (const char *)data : "no options");

sb->s_magic = AFFS_SUPER_MAGIC;
@@ -548,8 +582,6 @@ affs_remount(struct super_block *sb, int *flags, char *data)
}

flush_delayed_work(&sbi->sb_work);
- if (new_opts)
- replace_mount_options(sb, new_opts);

sbi->s_flags = mount_flags;
sbi->s_mode = mode;