> Sent: Sunday, August 12, 2018 at 9:33 AM
> From: "Qu Wenruo" <w...@suse.com>
> To: linux-btrfs@vger.kernel.org, dan.meril...@gmail.com
> Subject: [PATCH] btrfs-progs: rescue: Add ability to disable quota offline
>
> Provide an offline tool to disable quota.
>
> For kernel which skip_balance doesn't work, there is no way to disable
> quota on huge fs with balance, as quota will cause balance to hang for a
> long long time for each tree block switch.
>
Make sense the use case.
> So add an offline rescue tool to disable quota.
>
> Reported-by: Dan Merillat <dan.meril...@gmail.com>
> Signed-off-by: Qu Wenruo <w...@suse.com>
Some nitpicks below.
After fixes them, you can add tag:
Reviewed-by: Su Yue <suy.f...@cn.fujitsu.com>
> ---
> This can patch can be fetched from github repo:
> https://github.com/adam900710/btrfs-progs/tree/quota_disable
> ---
> Documentation/btrfs-rescue.asciidoc | 6 +++
> cmds-rescue.c | 80 +++++++++++++++++++++++++++++
> 2 files changed, 86 insertions(+)
>
> diff --git a/Documentation/btrfs-rescue.asciidoc
> b/Documentation/btrfs-rescue.asciidoc
> index f94a0ff2b45e..fb088c1a768a 100644
> --- a/Documentation/btrfs-rescue.asciidoc
> +++ b/Documentation/btrfs-rescue.asciidoc
> @@ -31,6 +31,12 @@ help.
> NOTE: Since *chunk-recover* will scan the whole device, it will be *VERY*
> slow
> especially executed on a large device.
>
> +*disable-quota* <device>::
> +disable quota offline
> ++
> +Acts as a fallback method to disable quota for case where mount hangs due to
> +balance and quota.
> +
> *fix-device-size* <device>::
> fix device size and super block total bytes values that are do not match
> +
> diff --git a/cmds-rescue.c b/cmds-rescue.c
> index 38c4ab9b2ef6..c7cd92427e9d 100644
> --- a/cmds-rescue.c
> +++ b/cmds-rescue.c
> @@ -250,6 +250,84 @@ out:
> return !!ret;
> }
>
> +static const char * const cmd_rescue_disable_quota_usage[] = {
> + "btrfs rescue disable-quota <device>",
> + "Disable quota, especially useful for balance mount hang when quota
> enabled",
> + "",
> + NULL
> +};
> +
> +static int cmd_rescue_disable_quota(int argc, char **argv)
> +{
> + struct btrfs_trans_handle *trans;
> + struct btrfs_fs_info *fs_info;
> + struct btrfs_path path;
> + struct btrfs_root *root;
> + struct btrfs_qgroup_status_item *qi;
> + struct btrfs_key key;
> + char *devname;
> + int ret;
> +
> + clean_args_no_options(argc, argv, cmd_rescue_disable_quota_usage);
> + if (check_argc_exact(argc, 2))
> + usage(cmd_rescue_disable_quota_usage);
> +
> + devname = argv[optind];
> + ret = check_mounted(devname);
> + if (ret < 0) {
> + error("could not check mount status: %s", strerror(-ret));
> + return !!ret;
> + } else if (ret) {
> + error("%s is currently mounted", devname);
> + return !!ret;
> + }
> + fs_info = open_ctree_fs_info(devname, 0, 0, 0, OPEN_CTREE_WRITES);
Not undertstand why not add OPEN_CTREE_PARTIAL here?
The function is located in cmd-rescue, so may the FS is corrupted already?
> + if (!fs_info) {
> + error("could not open btrfs");
> + ret = -EIO;
> + return !!ret;
> + }
> + root = fs_info->quota_root;
> + if (!root) {
> + printf("Quota is not enabled, no need to modify the fs\n");
> + goto close;
> + }
> + btrfs_init_path(&path);
> + trans = btrfs_start_transaction(root, 1);
> + if (IS_ERR(trans)) {
> + ret = PTR_ERR(trans);
> + error("failed to start transaction: %s", strerror(-ret));
> + goto close;
> + }
> + key.objectid = 0;
> + key.type = BTRFS_QGROUP_STATUS_KEY;
> + key.offset = 0;
> + ret = btrfs_search_slot(trans, root, &key, &path, 0, 1);
> + if (ret < 0) {
> + error("failed to search tree: %s", strerror(-ret));
> + goto close;
> + }
> + if (ret > 0) {
> + printf(
> + "qgroup status item not found, not need to modify the fs");
nits: s/qgroup/Qgroup and a linebreaker is needed.
> + ret = 0;
> + goto release;
> + }
> + qi = btrfs_item_ptr(path.nodes[0], path.slots[0],
> + struct btrfs_qgroup_status_item);
> + btrfs_set_qgroup_status_flags(path.nodes[0], qi,
> + BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT);
> + btrfs_mark_buffer_dirty(path.nodes[0]);
> + ret = btrfs_commit_transaction(trans, root);
> + if (ret < 0)
> + error("failed to commit transaction: %s", strerror(-ret));
> +release:
> + btrfs_release_path(&path);
> +close:
> + close_ctree(fs_info->tree_root);
> + return !!ret;
> +}
> +
> static const char rescue_cmd_group_info[] =
> "toolbox for specific rescue operations";
>
> @@ -262,6 +340,8 @@ const struct cmd_group rescue_cmd_group = {
> { "zero-log", cmd_rescue_zero_log, cmd_rescue_zero_log_usage,
> NULL, 0},
> { "fix-device-size", cmd_rescue_fix_device_size,
> cmd_rescue_fix_device_size_usage, NULL, 0},
> + { "disable-quota", cmd_rescue_disable_quota,
> + cmd_rescue_disable_quota_usage, NULL, 0},
> NULL_CMD_STRUCT
> }
> };
> --
> 2.18.0
>
>
