Linux-BTRFS Archive on lore.kernel.org
 help / color / Atom feed
From: Qu Wenruo <quwenruo.btrfs@gmx.com>
To: Anand Jain <anand.jain@oracle.com>, Qu Wenruo <wqu@suse.com>,
	linux-btrfs@vger.kernel.org
Subject: Re: [PATCH v2 7/7] btrfs-progs: btrfstune: Allow to enable bg-tree feature offline
Date: Thu, 17 Oct 2019 12:28:34 +0800
Message-ID: <777f249e-7198-8ec3-875d-244253d2ae3d@gmx.com> (raw)
In-Reply-To: <92f936ed-74eb-5c6e-2bf7-6226cdef14fd@oracle.com>

[-- Attachment #1.1: Type: text/plain, Size: 6254 bytes --]



On 2019/10/17 下午12:17, Anand Jain wrote:
> 
>  Depending on the size of the FS the convert may take longer, further
>  fatal error (power loss; pid kill) may leave the FS in a state where
>  the bg items are in both extent-tree and bg-tree.

That's why I'm using one transaction to convert them all.

So if the convert get interrutped, we're still safe.

Thanks,
Qu
> 
>  The lessons which lead to the implementation of metadata_uuid fsid
>  suggests, for conversions its better to use the btrfstune to only
>  flag the bg convert requirement and let the kernel handle of migration
>  of the bg items from the extent-tree to the bg-tree as and when the
>  bg-items are written.
> 
> Thanks, Anand
> 
> 
> On 10/8/19 12:49 PM, Qu Wenruo wrote:
>> Add a new option '-b' for btrfstune, to enable bg-tree feature for a
>> unmounted fs.
>>
>> This feature will convert all BLOCK_GROUP_ITEMs in extent tree to bg
>> tree, by reusing the existing btrfs_convert_to_bg_tree() function.
>>
>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>> ---
>>   Documentation/btrfstune.asciidoc |  6 +++++
>>   btrfstune.c                      | 44 ++++++++++++++++++++++++++++++--
>>   2 files changed, 48 insertions(+), 2 deletions(-)
>>
>> diff --git a/Documentation/btrfstune.asciidoc
>> b/Documentation/btrfstune.asciidoc
>> index 1d6bc98deed8..ed54c2e1597f 100644
>> --- a/Documentation/btrfstune.asciidoc
>> +++ b/Documentation/btrfstune.asciidoc
>> @@ -26,6 +26,12 @@ means.  Please refer to the 'FILESYSTEM FEATURES'
>> in `btrfs`(5).
>>   OPTIONS
>>   -------
>>   +-b::
>> +(since kernel: 5.x)
>> ++
>> +enable bg-tree feature (faster mount time for large fs), enabled by mkfs
>> +feature 'bg-tree'.
>> +
>>   -f::
>>   Allow dangerous changes, e.g. clear the seeding flag or change fsid.
>> Make sure
>>   that you are aware of the dangers.
>> diff --git a/btrfstune.c b/btrfstune.c
>> index afa3aae35412..aa1ac568aef0 100644
>> --- a/btrfstune.c
>> +++ b/btrfstune.c
>> @@ -476,11 +476,39 @@ static void print_usage(void)
>>       printf("\t-m          change fsid in metadata_uuid to a random
>> UUID\n");
>>       printf("\t            (incompat change, more lightweight than
>> -u|-U)\n");
>>       printf("\t-M UUID     change fsid in metadata_uuid to UUID\n");
>> +    printf("\t-b          enable bg-tree feature (mkfs: bg-tree, for
>> faster mount time)\n");
>>       printf("  general:\n");
>>       printf("\t-f          allow dangerous operations, make sure that
>> you are aware of the dangers\n");
>>       printf("\t--help      print this help\n");
>>   }
>>   +static int convert_to_bg_tree(struct btrfs_fs_info *fs_info)
>> +{
>> +    struct btrfs_trans_handle *trans;
>> +    int ret;
>> +
>> +    trans = btrfs_start_transaction(fs_info->tree_root, 1);
>> +    if (IS_ERR(trans)) {
>> +        ret = PTR_ERR(trans);
>> +        errno = -ret;
>> +        error("failed to start transaction: %m");
>> +        return ret;
>> +    }
>> +    ret = btrfs_convert_to_bg_tree(trans);
>> +    if (ret < 0) {
>> +        errno = -ret;
>> +        error("failed to convert: %m");
>> +        btrfs_abort_transaction(trans, ret);
>> +        return ret;
>> +    }
>> +    ret = btrfs_commit_transaction(trans, fs_info->tree_root);
>> +    if (ret < 0) {
>> +        errno = -ret;
>> +        error("failed to commit transaction: %m");
>> +    }
>> +    return ret;
>> +}
>> +
>>   int BOX_MAIN(btrfstune)(int argc, char *argv[])
>>   {
>>       struct btrfs_root *root;
>> @@ -491,6 +519,7 @@ int BOX_MAIN(btrfstune)(int argc, char *argv[])
>>       u64 seeding_value = 0;
>>       int random_fsid = 0;
>>       int change_metadata_uuid = 0;
>> +    bool to_bg_tree = false;
>>       char *new_fsid_str = NULL;
>>       int ret;
>>       u64 super_flags = 0;
>> @@ -501,7 +530,7 @@ int BOX_MAIN(btrfstune)(int argc, char *argv[])
>>               { "help", no_argument, NULL, GETOPT_VAL_HELP},
>>               { NULL, 0, NULL, 0 }
>>           };
>> -        int c = getopt_long(argc, argv, "S:rxfuU:nmM:", long_options,
>> NULL);
>> +        int c = getopt_long(argc, argv, "S:rxfuU:nmM:b",
>> long_options, NULL);
>>             if (c < 0)
>>               break;
>> @@ -539,6 +568,9 @@ int BOX_MAIN(btrfstune)(int argc, char *argv[])
>>               ctree_flags |= OPEN_CTREE_IGNORE_FSID_MISMATCH;
>>               change_metadata_uuid = 1;
>>               break;
>> +        case 'b':
>> +            to_bg_tree = true;
>> +            break;
>>           case GETOPT_VAL_HELP:
>>           default:
>>               print_usage();
>> @@ -556,7 +588,7 @@ int BOX_MAIN(btrfstune)(int argc, char *argv[])
>>           return 1;
>>       }
>>       if (!super_flags && !seeding_flag && !(random_fsid ||
>> new_fsid_str) &&
>> -        !change_metadata_uuid) {
>> +        !change_metadata_uuid && !to_bg_tree) {
>>           error("at least one option should be specified");
>>           print_usage();
>>           return 1;
>> @@ -602,6 +634,14 @@ int BOX_MAIN(btrfstune)(int argc, char *argv[])
>>           return 1;
>>       }
>>   +    if (to_bg_tree) {
>> +        ret = convert_to_bg_tree(root->fs_info);
>> +        if (ret < 0) {
>> +            errno = -ret;
>> +            error("failed to convert to bg-tree feature: %m");
>> +            goto out;
>> +        }
>> +    }
>>       if (seeding_flag) {
>>           if (btrfs_fs_incompat(root->fs_info, METADATA_UUID)) {
>>               fprintf(stderr, "SEED flag cannot be changed on a
>> metadata-uuid changed fs\n");
>>
> 


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

  reply index

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-08  4:49 [PATCH v2 0/7] btrfs-progs: Support for BG_TREE feature Qu Wenruo
2019-10-08  4:49 ` [PATCH v2 1/7] btrfs-progs: Refactor excluded extent functions to use fs_info Qu Wenruo
2019-10-08  9:22   ` Johannes Thumshirn
2019-10-17  2:16   ` Anand Jain
2019-10-08  4:49 ` [PATCH v2 2/7] btrfs-progs: Refactor btrfs_read_block_groups() Qu Wenruo
2019-10-17  3:23   ` Anand Jain
2019-10-17  4:33     ` Qu Wenruo
2019-10-17  5:08       ` Anand Jain
2019-10-08  4:49 ` [PATCH v2 3/7] btrfs-progs: Enable read-write ability for 'bg_tree' feature Qu Wenruo
2019-10-17  4:56   ` Anand Jain
2019-10-08  4:49 ` [PATCH v2 4/7] btrfs-progs: mkfs: Introduce -O bg-tree Qu Wenruo
2019-10-08  8:16   ` [PATCH v2.1 " Qu Wenruo
2019-10-08  4:49 ` [PATCH v2 5/7] btrfs-progs: dump-tree/dump-super: Introduce support for bg tree Qu Wenruo
2019-10-08  4:49 ` [PATCH v2 6/7] btrfs-progs: check: Introduce support for bg-tree feature Qu Wenruo
2019-10-08  4:49 ` [PATCH v2 7/7] btrfs-progs: btrfstune: Allow to enable bg-tree feature offline Qu Wenruo
2019-10-17  4:17   ` Anand Jain
2019-10-17  4:28     ` Qu Wenruo [this message]
2019-10-14 15:17 ` [PATCH v2 0/7] btrfs-progs: Support for BG_TREE feature David Sterba
2019-10-15  0:32   ` Qu Wenruo
2019-10-16 11:16     ` David Sterba
2019-10-16 11:19       ` Qu WenRuo
2019-10-18 17:27         ` David Sterba
2019-10-19  0:04           ` Qu Wenruo
2019-10-21 15:44             ` David Sterba
2019-10-22  0:49               ` Qu Wenruo
2019-10-22  6:30                 ` Qu Wenruo
2019-10-22 12:23                   ` David Sterba
2019-10-22 12:27                     ` Qu Wenruo

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=777f249e-7198-8ec3-875d-244253d2ae3d@gmx.com \
    --to=quwenruo.btrfs@gmx.com \
    --cc=anand.jain@oracle.com \
    --cc=linux-btrfs@vger.kernel.org \
    --cc=wqu@suse.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-BTRFS Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-btrfs/0 linux-btrfs/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-btrfs linux-btrfs/ https://lore.kernel.org/linux-btrfs \
		linux-btrfs@vger.kernel.org
	public-inbox-index linux-btrfs

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-btrfs


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git