Re: [PATCH] btrfs: add error messages to all unrecognized mount options

[Anand Jain <anand.jain@xxxxxxxxxx>]

LGTM.
Reviewed-by: Anand Jain <anand.jain@xxxxxxxxxx>

While we are on this topic-
Not all valid mount options get printed either. I sent a patch a long 
time back [1] to fix it. If there is enough interest, I could revive it.

[1]
[PATCH v2] btrfs: add mount umount logs



On 6/6/22 16:38, David Sterba wrote:
> Almost none of the errors stemming from a valid mount option but wrong
> value prints a descriptive message which would help to identify why
> mount failed. Like in the linked report:
>
>    $ uname -r
>    v4.19
>    $ mount -o compress=zstd /dev/sdb /mnt
>    mount: /mnt: wrong fs type, bad option, bad superblock on
>    /dev/sdb, missing codepage or helper program, or other error.
>    $ dmesg
>    ...
>    BTRFS error (device sdb): open_ctree failed
>
> Errors caused by memory allocation failures are left out as it's not a
> user error so reporting that would be confusing.
>
> Link: https://lore.kernel.org/linux-btrfs/9c3fec36-fc61-3a33-4977-a7e207c3fa4e@xxxxxx/
> CC: stable@xxxxxxxxxxxxxxx # 4.9+
> Signed-off-by: David Sterba <dsterba@xxxxxxxx>
> ---
>   fs/btrfs/super.c | 39 ++++++++++++++++++++++++++++++++-------
>   1 file changed, 32 insertions(+), 7 deletions(-)
>
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index d8e2eac0417e..719dda57dc7a 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -764,6 +764,8 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
>   				compress_force = false;
>   				no_compress++;
>   			} else {
> +				btrfs_err(info, "unrecognized compression value %s",
> +					  args[0].from);
>   				ret = -EINVAL;
>   				goto out;
>   			}
> @@ -822,8 +824,11 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
>   		case Opt_thread_pool:
>   			ret = match_int(&args[0], &intarg);
>   			if (ret) {
> +				btrfs_err(info, "unrecognized thread_pool value %s",
> +					  args[0].from);
>   				goto out;
>   			} else if (intarg == 0) {
> +				btrfs_err(info, "invalid value 0 for thread_pool");
>   				ret = -EINVAL;
>   				goto out;
>   			}
> @@ -884,8 +889,11 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
>   			break;
>   		case Opt_ratio:
>   			ret = match_int(&args[0], &intarg);
> -			if (ret)
> +			if (ret) {
> +				btrfs_err(info, "unrecognized metadata_ratio value %s",
> +					  args[0].from);
>   				goto out;
> +			}
>   			info->metadata_ratio = intarg;
>   			btrfs_info(info, "metadata ratio %u",
>   				   info->metadata_ratio);
> @@ -902,6 +910,8 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
>   				btrfs_set_and_info(info, DISCARD_ASYNC,
>   						   "turning on async discard");
>   			} else {
> +				btrfs_err(info, "unrecognized discard mode value %s",
> +					  args[0].from);
>   				ret = -EINVAL;
>   				goto out;
>   			}
> @@ -934,6 +944,8 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
>   				btrfs_set_and_info(info, FREE_SPACE_TREE,
>   						   "enabling free space tree");
>   			} else {
> +				btrfs_err(info, "unrecognized space_cache value %s",
> +					  args[0].from);
>   				ret = -EINVAL;
>   				goto out;
>   			}
> @@ -1015,8 +1027,12 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
>   			break;
>   		case Opt_check_integrity_print_mask:
>   			ret = match_int(&args[0], &intarg);
> -			if (ret)
> +			if (ret) {
> +				btrfs_err(info,
> +				"unrecognized check_integrity_print_mask value %s",
> +					args[0].from);
>   				goto out;
> +			}
>   			info->check_integrity_print_mask = intarg;
>   			btrfs_info(info, "check_integrity_print_mask 0x%x",
>   				   info->check_integrity_print_mask);
> @@ -1031,13 +1047,15 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
>   			goto out;
>   #endif
>   		case Opt_fatal_errors:
> -			if (strcmp(args[0].from, "panic") == 0)
> +			if (strcmp(args[0].from, "panic") == 0) {
>   				btrfs_set_opt(info->mount_opt,
>   					      PANIC_ON_FATAL_ERROR);
> -			else if (strcmp(args[0].from, "bug") == 0)
> +			} else if (strcmp(args[0].from, "bug") == 0) {
>   				btrfs_clear_opt(info->mount_opt,
>   					      PANIC_ON_FATAL_ERROR);
> -			else {
> +			} else {
> +				btrfs_err(info, "unrecognized fatal_errors value %s",
> +					  args[0].from);
>   				ret = -EINVAL;
>   				goto out;
>   			}
> @@ -1045,8 +1063,12 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
>   		case Opt_commit_interval:
>   			intarg = 0;
>   			ret = match_int(&args[0], &intarg);
> -			if (ret)
> +			if (ret) {
> +				btrfs_err(info, "unrecognized commit_interval value %s",
> +					  args[0].from);
> +				ret = -EINVAL;
>   				goto out;
> +			}
>   			if (intarg == 0) {
>   				btrfs_info(info,
>   					   "using default commit interval %us",
> @@ -1060,8 +1082,11 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
>   			break;
>   		case Opt_rescue:
>   			ret = parse_rescue_options(info, args[0].from);
> -			if (ret < 0)
> +			if (ret < 0) {
> +				btrfs_err(info, "unrecognized rescue value %s",
> +					  args[0].from);
>   				goto out;
> +			}
>   			break;
>   #ifdef CONFIG_BTRFS_DEBUG
>   		case Opt_fragment_all: