From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([59.151.112.132]:50969 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1750812AbdEQBNC (ORCPT ); Tue, 16 May 2017 21:13:02 -0400 Subject: Re: [RFC PATCH v3.1 3/6] btrfs: qgroup: Return actually freed bytes for qgroup release or free data To: , , References: <20170512033046.31981-1-quwenruo@cn.fujitsu.com> <20170512033046.31981-4-quwenruo@cn.fujitsu.com> <20170516142306.GE4065@twin.jikos.cz> From: Qu Wenruo Message-ID: Date: Wed, 17 May 2017 09:12:58 +0800 MIME-Version: 1.0 In-Reply-To: <20170516142306.GE4065@twin.jikos.cz> Content-Type: text/plain; charset="utf-8"; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: At 05/16/2017 10:23 PM, David Sterba wrote: > On Fri, May 12, 2017 at 11:30:43AM +0800, Qu Wenruo wrote: >> btrfs_qgroup_release/free_data() only returns 0 or minus error >> number(ENOMEM is the only possible error). > > "btrfs_qgroup_release/free_data() only returns 0 or a negative error > number (ENOMEM is the only possible error)." > >> This is normally good enough, but sometimes we need the accurate byte >> number it freed/released. >> >> Change it to return actually released/freed bytenr number instead of 0 >> for success. >> And slightly modify related extent_changeset structure, since in btrfs >> one none-hole data extent won't be larger than 128M, so "unsigned int" > ^^^^^^^^^ > NO_HOLES or no-hole > >> is large enough for the use case. >> >> Signed-off-by: Qu Wenruo >> --- >> fs/btrfs/extent-tree.c | 2 +- >> fs/btrfs/extent_io.h | 2 +- >> fs/btrfs/qgroup.c | 1 + >> 3 files changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c >> index e390451c72e6..4f62696131a6 100644 >> --- a/fs/btrfs/extent-tree.c >> +++ b/fs/btrfs/extent-tree.c >> @@ -4298,7 +4298,7 @@ int btrfs_check_data_free_space(struct inode *inode, u64 start, u64 len) >> >> /* Use new btrfs_qgroup_reserve_data to reserve precious data space. */ >> ret = btrfs_qgroup_reserve_data(inode, start, len); >> - if (ret) >> + if (ret < 0) >> btrfs_free_reserved_data_space_noquota(inode, start, len); >> return ret; >> } >> diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h >> index 1eafa2f0ede3..cc1b08fa9fe7 100644 >> --- a/fs/btrfs/extent_io.h >> +++ b/fs/btrfs/extent_io.h >> @@ -205,7 +205,7 @@ struct extent_buffer { >> */ >> struct extent_changeset { >> /* How many bytes are set/cleared in this operation */ >> - u64 bytes_changed; >> + unsigned int bytes_changed; > > The alignment constraints will insert 4 bytes anyway, so we don't save > any space, but unsigned int is fine here, as we're not going to utilize u64. Sorry, I just realized that extent_state in extent_io_tree can be merged with each other. So (state->end - state->start + 1) can overflow unsigned int. I'll skip this modification in next update, and apply the grammar comment. Thanks, Qu > >> /* Changed ranges */ >> struct ulist range_changed; >> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c >> index 9f01c25469f7..ad2e99491395 100644 >> --- a/fs/btrfs/qgroup.c >> +++ b/fs/btrfs/qgroup.c >> @@ -2886,6 +2886,7 @@ static int __btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len, >> btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info, >> BTRFS_I(inode)->root->objectid, >> changeset.bytes_changed); >> + ret = changeset.bytes_changed; >> out: >> ulist_release(&changeset.range_changed); >> return ret; >> -- >> 2.12.2 >> >> >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > >