Re: [PATCH V3 7/7] f2fs: switch to the new mount api

[Chao Yu <chao@kernel.org>]

On 4/24/25 01:08, Eric Sandeen wrote:
> From: Hongbo Li <lihongbo22@huawei.com>
> 
> The new mount api will execute .parse_param, .init_fs_context, .get_tree
> and will call .remount if remount happened. So we add the necessary
> functions for the fs_context_operations. If .init_fs_context is added,
> the old .mount should remove.
> 
> See Documentation/filesystems/mount_api.rst for more information.

mkfs.f2fs -f -O extra_attr,flexible_inline_xattr /dev/vdb
mount -o inline_xattr_size=512 /dev/vdb /mnt/f2fs
mount: /mnt/f2fs: wrong fs type, bad option, bad superblock on /dev/vdb, missing codepage or helper program, or other error.
       dmesg(1) may have more information after failed mount system call.
dmesg
[ 1758.202282] F2FS-fs (vdb): Image doesn't support compression
[ 1758.202286] F2FS-fs (vdb): inline_xattr_size option should be set with inline_xattr option

Eric, Hongbo, can you please take a look at this issue?

Thanks,

> 
> Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
> [sandeen: forward port]
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---
>  fs/f2fs/super.c | 156 +++++++++++++++++++-----------------------------
>  1 file changed, 62 insertions(+), 94 deletions(-)
> 
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 37497fd80bb9..041bd6c482a0 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -1141,47 +1141,6 @@ static int f2fs_parse_param(struct fs_context *fc, struct fs_parameter *param)
>  	return 0;
>  }
>  
> -static int parse_options(struct fs_context *fc, char *options)
> -{
> -	struct fs_parameter param;
> -	char *key;
> -	int ret;
> -
> -	if (!options)
> -		return 0;
> -
> -	while ((key = strsep(&options, ",")) != NULL) {
> -		if (*key) {
> -			size_t v_len = 0;
> -			char *value = strchr(key, '=');
> -
> -			param.type = fs_value_is_flag;
> -			param.string = NULL;
> -
> -			if (value) {
> -				if (value == key)
> -					continue;
> -
> -				*value++ = 0;
> -				v_len = strlen(value);
> -				param.string = kmemdup_nul(value, v_len, GFP_KERNEL);
> -				if (!param.string)
> -					return -ENOMEM;
> -				param.type = fs_value_is_string;
> -			}
> -
> -			param.key = key;
> -			param.size = v_len;
> -
> -			ret = f2fs_parse_param(fc, &param);
> -			kfree(param.string);
> -			if (ret < 0)
> -				return ret;
> -		}
> -	}
> -	return 0;
> -}
> -
>  /*
>   * Check quota settings consistency.
>   */
> @@ -2583,13 +2542,12 @@ static void f2fs_enable_checkpoint(struct f2fs_sb_info *sbi)
>  	f2fs_flush_ckpt_thread(sbi);
>  }
>  
> -static int f2fs_remount(struct super_block *sb, int *flags, char *data)
> +static int __f2fs_remount(struct fs_context *fc, struct super_block *sb)
>  {
>  	struct f2fs_sb_info *sbi = F2FS_SB(sb);
>  	struct f2fs_mount_info org_mount_opt;
> -	struct f2fs_fs_context ctx;
> -	struct fs_context fc;
>  	unsigned long old_sb_flags;
> +	unsigned int flags = fc->sb_flags;
>  	int err;
>  	bool need_restart_gc = false, need_stop_gc = false;
>  	bool need_restart_flush = false, need_stop_flush = false;
> @@ -2635,7 +2593,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
>  #endif
>  
>  	/* recover superblocks we couldn't write due to previous RO mount */
> -	if (!(*flags & SB_RDONLY) && is_sbi_flag_set(sbi, SBI_NEED_SB_WRITE)) {
> +	if (!(flags & SB_RDONLY) && is_sbi_flag_set(sbi, SBI_NEED_SB_WRITE)) {
>  		err = f2fs_commit_super(sbi, false);
>  		f2fs_info(sbi, "Try to recover all the superblocks, ret: %d",
>  			  err);
> @@ -2645,21 +2603,11 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
>  
>  	default_options(sbi, true);
>  
> -	memset(&fc, 0, sizeof(fc));
> -	memset(&ctx, 0, sizeof(ctx));
> -	fc.fs_private = &ctx;
> -	fc.purpose = FS_CONTEXT_FOR_RECONFIGURE;
> -
> -	/* parse mount options */
> -	err = parse_options(&fc, data);
> -	if (err)
> -		goto restore_opts;
> -
> -	err = f2fs_check_opt_consistency(&fc, sb);
> +	err = f2fs_check_opt_consistency(fc, sb);
>  	if (err < 0)
>  		goto restore_opts;
>  
> -	f2fs_apply_options(&fc, sb);
> +	f2fs_apply_options(fc, sb);
>  
>  #ifdef CONFIG_BLK_DEV_ZONED
>  	if (f2fs_sb_has_blkzoned(sbi) &&
> @@ -2678,20 +2626,20 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
>  	 * Previous and new state of filesystem is RO,
>  	 * so skip checking GC and FLUSH_MERGE conditions.
>  	 */
> -	if (f2fs_readonly(sb) && (*flags & SB_RDONLY))
> +	if (f2fs_readonly(sb) && (flags & SB_RDONLY))
>  		goto skip;
>  
> -	if (f2fs_dev_is_readonly(sbi) && !(*flags & SB_RDONLY)) {
> +	if (f2fs_dev_is_readonly(sbi) && !(flags & SB_RDONLY)) {
>  		err = -EROFS;
>  		goto restore_opts;
>  	}
>  
>  #ifdef CONFIG_QUOTA
> -	if (!f2fs_readonly(sb) && (*flags & SB_RDONLY)) {
> +	if (!f2fs_readonly(sb) && (flags & SB_RDONLY)) {
>  		err = dquot_suspend(sb, -1);
>  		if (err < 0)
>  			goto restore_opts;
> -	} else if (f2fs_readonly(sb) && !(*flags & SB_RDONLY)) {
> +	} else if (f2fs_readonly(sb) && !(flags & SB_RDONLY)) {
>  		/* dquot_resume needs RW */
>  		sb->s_flags &= ~SB_RDONLY;
>  		if (sb_any_quota_suspended(sb)) {
> @@ -2747,7 +2695,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
>  		goto restore_opts;
>  	}
>  
> -	if ((*flags & SB_RDONLY) && test_opt(sbi, DISABLE_CHECKPOINT)) {
> +	if ((flags & SB_RDONLY) && test_opt(sbi, DISABLE_CHECKPOINT)) {
>  		err = -EINVAL;
>  		f2fs_warn(sbi, "disabling checkpoint not compatible with read-only");
>  		goto restore_opts;
> @@ -2758,7 +2706,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
>  	 * or if background_gc = off is passed in mount
>  	 * option. Also sync the filesystem.
>  	 */
> -	if ((*flags & SB_RDONLY) ||
> +	if ((flags & SB_RDONLY) ||
>  			(F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_OFF &&
>  			!test_opt(sbi, GC_MERGE))) {
>  		if (sbi->gc_thread) {
> @@ -2772,7 +2720,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
>  		need_stop_gc = true;
>  	}
>  
> -	if (*flags & SB_RDONLY) {
> +	if (flags & SB_RDONLY) {
>  		sync_inodes_sb(sb);
>  
>  		set_sbi_flag(sbi, SBI_IS_DIRTY);
> @@ -2785,7 +2733,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
>  	 * We stop issue flush thread if FS is mounted as RO
>  	 * or if flush_merge is not passed in mount option.
>  	 */
> -	if ((*flags & SB_RDONLY) || !test_opt(sbi, FLUSH_MERGE)) {
> +	if ((flags & SB_RDONLY) || !test_opt(sbi, FLUSH_MERGE)) {
>  		clear_opt(sbi, FLUSH_MERGE);
>  		f2fs_destroy_flush_cmd_control(sbi, false);
>  		need_restart_flush = true;
> @@ -2827,7 +2775,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
>  	 * triggered while remount and we need to take care of it before
>  	 * returning from remount.
>  	 */
> -	if ((*flags & SB_RDONLY) || test_opt(sbi, DISABLE_CHECKPOINT) ||
> +	if ((flags & SB_RDONLY) || test_opt(sbi, DISABLE_CHECKPOINT) ||
>  			!test_opt(sbi, MERGE_CHECKPOINT)) {
>  		f2fs_stop_ckpt_thread(sbi);
>  	} else {
> @@ -2854,7 +2802,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
>  		(test_opt(sbi, POSIX_ACL) ? SB_POSIXACL : 0);
>  
>  	limit_reserve_root(sbi);
> -	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
> +	fc->sb_flags = (flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
>  
>  	sbi->umount_lock_holder = NULL;
>  	return 0;
> @@ -3523,7 +3471,6 @@ static const struct super_operations f2fs_sops = {
>  	.freeze_fs	= f2fs_freeze,
>  	.unfreeze_fs	= f2fs_unfreeze,
>  	.statfs		= f2fs_statfs,
> -	.remount_fs	= f2fs_remount,
>  	.shutdown	= f2fs_shutdown,
>  };
>  
> @@ -4745,16 +4692,13 @@ static void f2fs_tuning_parameters(struct f2fs_sb_info *sbi)
>  	sbi->readdir_ra = true;
>  }
>  
> -static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> +static int f2fs_fill_super(struct super_block *sb, struct fs_context *fc)
>  {
>  	struct f2fs_sb_info *sbi;
>  	struct f2fs_super_block *raw_super;
> -	struct f2fs_fs_context ctx;
> -	struct fs_context fc;
>  	struct inode *root;
>  	int err;
>  	bool skip_recovery = false, need_fsck = false;
> -	char *options = NULL;
>  	int recovery, i, valid_super_block;
>  	struct curseg_info *seg_i;
>  	int retry_cnt = 1;
> @@ -4767,9 +4711,6 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
>  	raw_super = NULL;
>  	valid_super_block = -1;
>  	recovery = 0;
> -	memset(&fc, 0, sizeof(fc));
> -	memset(&ctx, 0, sizeof(ctx));
> -	fc.fs_private = &ctx;
>  
>  	/* allocate memory for f2fs-specific super block info */
>  	sbi = kzalloc(sizeof(struct f2fs_sb_info), GFP_KERNEL);
> @@ -4820,22 +4761,12 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
>  						sizeof(raw_super->uuid));
>  
>  	default_options(sbi, false);
> -	/* parse mount options */
> -	options = kstrdup((const char *)data, GFP_KERNEL);
> -	if (data && !options) {
> -		err = -ENOMEM;
> -		goto free_sb_buf;
> -	}
> -
> -	err = parse_options(&fc, options);
> -	if (err)
> -		goto free_options;
>  
> -	err = f2fs_check_opt_consistency(&fc, sb);
> +	err = f2fs_check_opt_consistency(fc, sb);
>  	if (err < 0)
> -		goto free_options;
> +		goto free_sb_buf;
>  
> -	f2fs_apply_options(&fc, sb);
> +	f2fs_apply_options(fc, sb);
>  
>  	sb->s_maxbytes = max_file_blocks(NULL) <<
>  				le32_to_cpu(raw_super->log_blocksize);
> @@ -5160,7 +5091,6 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
>  		if (err)
>  			goto sync_free_meta;
>  	}
> -	kvfree(options);
>  
>  	/* recover broken superblock */
>  	if (recovery) {
> @@ -5255,7 +5185,6 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
>  		kfree(F2FS_OPTION(sbi).s_qf_names[i]);
>  #endif
>  	fscrypt_free_dummy_policy(&F2FS_OPTION(sbi).dummy_enc_policy);
> -	kvfree(options);
>  free_sb_buf:
>  	kfree(raw_super);
>  free_sbi:
> @@ -5271,14 +5200,39 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
>  	return err;
>  }
>  
> -static struct dentry *f2fs_mount(struct file_system_type *fs_type, int flags,
> -			const char *dev_name, void *data)
> +static int f2fs_get_tree(struct fs_context *fc)
>  {
> -	return mount_bdev(fs_type, flags, dev_name, data, f2fs_fill_super);
> +	return get_tree_bdev(fc, f2fs_fill_super);
> +}
> +
> +static int f2fs_reconfigure(struct fs_context *fc)
> +{
> +	struct super_block *sb = fc->root->d_sb;
> +
> +	return __f2fs_remount(fc, sb);
> +}
> +
> +static void f2fs_fc_free(struct fs_context *fc)
> +{
> +	struct f2fs_fs_context *ctx = fc->fs_private;
> +	int i;
> +
> +	if (!ctx)
> +		return;
> +
> +#ifdef CONFIG_QUOTA
> +	for (i = 0; i < MAXQUOTAS; i++)
> +		kfree(F2FS_CTX_INFO(ctx).s_qf_names[i]);
> +#endif
> +	fscrypt_free_dummy_policy(&F2FS_CTX_INFO(ctx).dummy_enc_policy);
> +	kfree(ctx);
>  }
>  
>  static const struct fs_context_operations f2fs_context_ops = {
>  	.parse_param	= f2fs_parse_param,
> +	.get_tree	= f2fs_get_tree,
> +	.reconfigure = f2fs_reconfigure,
> +	.free	= f2fs_fc_free,
>  };
>  
>  static void kill_f2fs_super(struct super_block *sb)
> @@ -5322,10 +5276,24 @@ static void kill_f2fs_super(struct super_block *sb)
>  	}
>  }
>  
> +static int f2fs_init_fs_context(struct fs_context *fc)
> +{
> +	struct f2fs_fs_context *ctx;
> +
> +	ctx = kzalloc(sizeof(struct f2fs_fs_context), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	fc->fs_private = ctx;
> +	fc->ops = &f2fs_context_ops;
> +
> +	return 0;
> +}
> +
>  static struct file_system_type f2fs_fs_type = {
>  	.owner		= THIS_MODULE,
>  	.name		= "f2fs",
> -	.mount		= f2fs_mount,
> +	.init_fs_context = f2fs_init_fs_context,
>  	.kill_sb	= kill_f2fs_super,
>  	.fs_flags	= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
>  };